Operating Instructions for Cat 1U-9400 Series Hydraulic Test Center {0784} Caterpillar

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Introduction

Important Safety Information

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Think Safety

Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.

Improper operation, lubrication, maintenance, or repair of this product can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair on this product until you have read and understood the operation, lubrication, maintenance, and repair information.

Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

The hazards are identified by the “Safety Alert Symbol” and followed by a “Signal Word” such as “DANGER”,“WARNING”, or “CAUTION”. The Safety Alert “WARNING” label is shown below.

A non-exhaustive list of operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are therefore, not all inclusive. If a tool, procedure, work method, or operating technique that is not recommended by Caterpillar is used, the operator must be sure that the procedures are safe. The operator must also be sure that the product will not be damaged or made unsafe by any unspecified procedures.

The information, specifications, and illustrations in this publication are based on information that was available at the time that the publication was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete and most current information before you start any job.

When replacement parts are required for this product, Caterpillar recommends using Cat replacement parts or parts with equivalent specifications including, but not limited to, physical dimensions, type, strength, and material.

Literature Information

This manual contains safety information, operation instructions and maintenance information and should be stored with the tool group.

Some photographs or illustrations in this publication may show details that can be different from your service tool. Guards and covers might have been removed for illustrative purposes.

Continuing improvement and advancement of product design might have caused changes to your service tool, which are not included in this publication.

Whenever a question arises regarding your service tool or this publication, consult Dealer Service Tools (DST) for the latest available information.

Safety Section

The Safety Section lists basic safety precautions.

Read and understand the basic precautions listed in the Safety Section before operating or performing maintenance and repair on this service tool.

General Information Section

The General Information Section describes tooling functions and features. The section provides useful information on individual parts, additional tooling, and resources.

Operation Section

The Operation Section is a reference for the new operator and a refresher for the experienced operator.

Photographs and illustrations guide the operator through correct procedures for using the tool group.

Operating techniques outlined in this publication are basic. Skill and techniques develop as the operator gains knowledge of the service tool and tool capabilities.

Maintenance Section

The Maintenance Section is a guide to tool inspection, cleaning, storage, and tool disposal

Service Parts Section

The Service Parts Section is a reference for parts identification and available part numbers.

Safety Section

Safety Icon Nomenclature

Personal Protection/Important Information

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Personal Protection/Important Information

Prohibited Action

Do not weld

No smoking

General Information Section

Introduction

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Cat 1U-9400 Series Hydraulic Test Centers can be used to test many Cat hydraulic components. This test center is ideal for testing hydrostatic and powershift transmissions, hydraulic pumps, motors, cylinders, and valves. Testing these components will assure that they are in good working order and properly adjusted before being installed on or in a machine. A Cat Hydraulic Test Center is constructed to withstand the rigors of continuous use and testing in various shop environments. It will give excellent service with minimum maintenance, as long as it is properly operated and maintained.

Cat dealers are investing in specialized test equipment for a very simple reason. Testing components after repair or rebuild saves the shop money, as well as field service time passed on to the customer. The dealer knows that only properly working Cat 1U-9400 Series Hydraulic Test Centers have a patented hydraulic system that allows for flexibility in component set-up to closely simulate "in-machine" conditions.

Reference

Bench Testing Hydraulic Components, Form NEHT5000.

Or visit our intranet web site at: http://productsupport.cat.com/dcd/cstg/prod/content.htm

Basic Capabilities

• Installation, testing and adjusting of transmissions, hydraulic pumps, motors, cylinders, and valves.

• Drive power to rotate existing hydraulic components, with reserve power for future designs.

• Oil flow to test component at controlled rates and pressures.

• Oil flow for pump testing by positive head pressure.

• Oil flow rate metering from the test component through any one of multiple routes. Four flowmeter-only circuits, two flowmeter circuits with load valves for pressurizing the test system. One circuit with load capabilities for testing closed circuit, bi-directional pumps.

Features and Specifications

Primary Drive System

• The main electric motor drives the hydrostatic system.

• 50 to 60 Hz from 200 to 450 hp.

• Units are available for standard commercial power, from 230 to 575 V, 3 phase, 50 Hz, or 60 Hz.

Hydrostatic System

Variable displacement piston pumps and motor capable of 0 to 2600 rpm, 0 to 43400 kPa (0 to 6000 psi) with a maximum of 2298 Nm (1194 lb.ft.) output torque.

Speed Control

Bi-directional and infinitely variable through full range to a maximum of 2550 rpm. The unit will maintain ± 6 rpm with normal load.

Oil Flow Out Systems

Variable 0 to 43400 kPa (0 to 6000 psi) oil flow up to 179 lpm (50 gpm) for general-purpose testing.

0 to 49600 kPa (0 to 7000 psi) oil flow up to 13 lpm (3.5 gpm) for pressure testing of relief valves and controlling pumps.

0 to 2760 kPa (0 to 400 psi) oil flow up to 17 lpm (4.5 gpm) for controlling pumps.

Super charge oil flow 1035 to 3450 kPa (150 to 500 psi) up to 189 lpm (67 gpm) (dependent on system conditions).

Lube flow out system for bearing and bushing lubrication of test component with a low flow and a maximum of 450 kPa (65 psi).

Pump suction system provides a positive head of oil by gravity flow from main reservoir, via a 101 mm (4 in) line to inlet of pump.

Oil Flow Monitoring Loops

Four monitoring loops through the test stand. These do not return directly to reservoir but can be configured to do so.

• Two loops monitor flow up to 320 lpm (85 gpm)

One loop for non-load flow monitoring.

One loop for loading test component with maximum pressure of 43400 kPa (6000 psi), with integral variable orifice to provide signal source for load sensing pumps.

• Two loops monitor flow up to 760 lpm (200 gpm)

One loop for non-load flow monitoring.

One loop for load testing component to maximum pressure of 43400 kPa (6000 psi)

• Closed Circuit Pump Test & Monitoring Loop

760 lpm (200 gpm) flow meter through 6 micron high-pressure filter with a bridge circuit and make up capabilities. Separate 3550 kPa (500 psi) heat exchanger for additional charge oil cooling.

• Return to Tank

Two connections return oil from test component to main reservoir through 10 micron filtration. These have no flow reading or pressure loading capabilities.

• Sump Pump System

Returns oil to main reservoir from work sump area at 208 lpm (55 gpm) through 5 micron high capacity filter.

• Pressure Monitoring Capabilities

Sixteen (16) Pressure Gauges of differing delineation can be used to monitor pressures from taps on the test component.

• Oil/water heat exchanger and integral tank heater with automatic temperature control.

Oil temperature is controlled by an adjustable water modulating valve. Tank heater is thermostatically controlled and oil is circulated during heat cycle.

• Extended Filtration

Integral 3 micron kidney loop system. Circulates oil in the main hydraulic tank during idle times and heating cycles.

Auxiliary pressure inlet. Allows filtration of a component's outlet flow before it enters a loading circuit. (0ptional Equipment)

Centrifugal Filters. Filter out sub-micronic particles that are suspended in the reservoir oil. (Optional Equipment)

General Tooling for the Hydraulic Test Center

Note: General tooling used on the test center and specific tooling used to attach Cat components to the bench are explained in NEHT5000, Bench Testing Hydraulic Components. Customized tool lists are available by contacting Cat Dealer Service Tools.

Dimensions and Capacities

Test Stand:

• 1232 liters (325 gallons) Main Reservoir

• Length 4065 mm (160 in)

• Width 2060 mm (81 in)

• Height 2260 mm (89 in)

• Weight 5910 kg (13,000 lb) (est.) Total weight is dependent upon horsepower and voltage.

Work Support Sump:

• 660 liter (175 gallons) Sump Pan

• Length 3676.6 mm (145 in)

• Width 2133.6 mm (84 in)

• Height 280 mm (11 in)

Oil Specifications

Recommended oil is SA-E10W Hydraulic Oil. For testing components at a lower temperature, Mobil DTE10/Excel 15 hydraulic oil is recommended. This will reduce the temperature at which a component can be tested, approximately 14°C (25°F) while maintaining the same viscosity characteristics as SAE 10W at higher temperature.

Note: If additional information is required for this oil, contact your Cat Dealer Service Tools representative.

General Functions of the Test Center

The 1U-9400 Series Hydraulic Test Center consists of: Hydrostatic System, Oil Flow Out System, Component Control and Monitoring System, a Sump System, and Return to Tank System.

1. The Hydrostatic System:

   Consists of an electric motor to turn a hydraulic pump, which produces a flow of oil under pressure. The oil is transmitted through hoses to a hydraulic motor and by turning the motor, produces mechanical power. Controls on this system enable the operator to infinitely vary the output speed from 0 to 2550 rpm, either clockwise or counterclockwise. The hydrostatic system is reliable and easily maintained.

2. The Oil Flow Out Systems:

   Oil may be supplied from any one of four ports in the test stand to the component being tested. Depending upon the system chosen, the flow will range from a gravity drain to pressures up to 49610 kPa (7000 psi).

3. The Component Control and Monitoring Systems:

   Oil may be routed from the test component to any one of four flowmeter loops in the test stand. The flowmeter loops monitor pressure and flow internally. In addition, pressure tabs on the test component can be connected to the test ports and monitored on the test center control panel. Depending on the system chosen, the flow monitoring will range from 0-320 lpm (85 gpm) or 0- 760 lpm (200 gpm) and loading can be controlled from 0 to 43400 kPa (0 to 6000 psi). Pressures can be monitored up to 49610 kPa (7000 psi). Control devices on test components can be supplied oil from two separate controllable sources and pressure limits. One from 0-4130 kPa (0-450 psi), one from 0-52500 kPa (0-7000 psi).

4. The Work Support Sump and Return to Tank System:

   Oil may return by either of two routes to the stand through two ports on the main manifold or directly from the sump. Any leaks from the test component or oil spills during testing are collected in the work support sump and automatically returned to the reservoir by a low-pressure sump pump. The sump oil level is controlled by a float switch, which is mounted in the sump.

   All 1U-9400 Hydraulic Test Centers are rigorously tested before shipment. All functions have been verified to meet or exceed specifications listed. Prior to initial start-up, it is recommended Cat Dealer Service Tools be consulted for installation requirement conformity and final commissioning guidelines. Upon installation, a Cat Dealer Service Tools representative will provide start-up assistance and training. Therefore, it is recommended that only basic functions be tested at this time.

Illustration 4	g02513076
Control Panel Front View

Gauges and Controls

(1) Input Torque: A digital meter that displays the input torque of the test component.

(2) Manual Motor Displacement: Analog Gauge that displays secondary fluid motor displacement in percent of maximum swashplate angle.

(3) Main Reservoir Temp: Analog Gauge that indicates the temperature of the oil in the main reservoir. The gauge reads in degrees Fahrenheit.

(4) Motor Amperage: An Analog Gauge that indicates main electric motor current.

(5) Inlet Pressure G1: An 8T-0840 Gauge that shows inlet pump suction. The gauge reads from 100 to 205 kPa (30 in) of mercury to 30 psi.

(6) Auxiliary Pressure G8: A 4C-4618 Gauge that shows auxiliary control pressure. The pressure is controlled by the Auxiliary Pressure Control C1. The gauge reads from 0 - 4130 kPa (0 - 600 psi).

(7) Auxiliary Pressure Control C1: A variable pressure reducer for supplying control pressure for test components. Its outlet port is S3. It will supply oil up to 17 lpm (4.5 gpm) and pressure is variable from 0 to 3100 kPa (0 to 450 psi). The pressure can be read on G8 Gauge.

(8) Hydrostatic Loop Pressure G2: A 1U-9697 Gauge that shows the pressure in the hydrostatic drive loop. The gauge reads from 0 - 52500 kPa (0 - 7500 psi).

(9) Flowmeter F1: A digital meter that displays the flow of the F1 Flowmeter. The meter reads from 7 - 200 gpm.

(10) Hydraulic Loop Pressure Control C2: A variable relief valve used to control the pressure on hydrostatic loop and test component circuit. It is variable from 0 - 43400 kPa (0 - 6000 psi). The pressure can be read on the Hydrostatic Loop Pressure G2.

(11) Auxiliary Pump Pressure G3: A 4C-4617 Gauge that shows the pressure of the auxiliary pump circuit. The gauge reads from 0 - 6890 kPa ( 0 - 1000 psi). Pressures go to 43400 kPa (6300 psi) in this circuit but is protected by a gauge minder.

(12) High Pump Pressure G9: A 1U-9697 Gauge that shows the pressure in the high pump pressure circuit. The gauge reads from 0 - 52500 kPa (0 - 7500 psi).

(13) Hydraulic Pump Pressure Control C3: A variable relief valve used to control the pressure of the high pump pressure circuit. It is variable from 0 - 52500 kPa (0 - 7000 psi). The pressure can be read on the High Pump Pressure Gauge G9.

(14) Auxiliary Pump Pressure G4: A 1U-9697 Gauge that shows the pressure in the Auxiliary Pump Circuit. The gauge reads from 0 - 46910 kPa (0 - 7000 psi).

(15) Flowmeter F2: A digital meter that displays the flow of the F2 Flowmeter. The meter reads from 4 - 85 gpm.

(16) Auxiliary Gauge Drain: A needle valve that allows the oil pressure to be drained from the Gauge Minder Valve in Gauge G3. It can also be used to remove trapped pressure from the auxiliary pump system.

(17) Auxiliary Pump Pressure Control C4: A variable relief valve used to control the pressure of the Auxiliary Pump Circuit. It is variable from 0 - 43400 kPa (0 - 6000 psi). The pressure can be read on the Auxiliary Pump Gauge G3 and G4.

(18) Pump Pressure Metered Flow G5: A gauge that shows the pressure in the F3 Flowmeter Loop. Pressure is monitored after the Pump Test Flow Limiter Control C8. The gauge reads from 0 - 52500 kPa (0 - 7500 psi).

(19) Super Charge Pressure G10: A gauge that shows the pressure in the super charge circuit. The gauge reads from 0 - 4130 kPa (0 - 600 psi).

(20) Super Charge Pressure Control C5: A variable relief valve used to control the pressure of the super charge circuit. It is variable from 1035 - 3445 kPa (150 - 500 psi). The pressure can be read on the Super Charge Pressure Gauge G10.

(21) Pump Load Pressure Gauge G6: A 1U-9697 Gauge that shows the pressure in the F3 Flowmeter Loop. Pressure is monitored at the load relief valve. The gauge reads from 0 - 52500 kPa ( 0 - 7500 psi).

(22) Flowmeter F3: A digital meter that displays the flow of the F3 Flowmeter. The meter reads from 4 to 85 gpm.

(23) Margin Pressure Gauge G11: A 1U-5793 Gauge monitors the pressures at Gauges G6 and G5 required when testing load sensing pumps. It has a magnetic movement so over pressure will not damage the unit. The gauge reads differential pressure from 0 - 4350 kPa (0 - 500 psi).

(24) Load Control C6: A variable relief valve used to control the pressure in the F3 Flowmeter Loop. It is variable from 0 - 43400 kPa (0 - 6000 psi).

(25) Pump Pressure G7: a 1U-9697 Gauge that shows the pressure in the F4 Flowmeter Loop. The gauge reads from 0 -52500 kPa (0 - 7500 psi).

(26) Flowmeter F4: A digital meter that displays the flow in the F4-Flowmeter Loop. The meter reads from 7 - 200 gpm.

(27) Input speed: A digital meter that displays the RPM of the drive shaft to the test component.

(28) Load Control C7: A variable relief valve used to control the pressure in the F4 Flowmter Loop. It is variable from 0 - 43400 kPa (0 - 6000 psi).

Test Gauges

(29 - 37) Pressure Gauges TP1 - TP9 are 8T-0850 Analog Gauges for monitoring pressures. The pressure taps are located under the main manifold. The gauges read from 0 - 1380 kPa (0 - 200 psi).

(38 - 39) Pressure Gauges TP10 - TP11 are 4C-4615 Analog Gauges for monitoring pressures. The pressure taps are located under the main manifold. The gauges read from 0 - 1380 kPa (0 - 200 psi).

(40) TP12 Pressure Gauge: A 4C-4614 Analog Gauge for monitoring pressures. The pressure tap is located under the main manifold. The gauge reads from 0 - 415 kPa (0 - 100 psi).

(41) TP13 Pressure Gauge: An 8T-0848 Analog Gauge for monitoring pressures. The pressure tap is located under the main manifold. The gauge reads 0 - 415 kPa (60 psi)

(42) TP14 Pressure Gauge: A 4C-4616 Analog Gauge for monitoring pressures. The pressure tap is located under the main manifold. The gauge reads from 0 - 52500 kPa (0 - 7500 psi).

(43) TP15 Pressure Gauge: An 8T-0852 Analog Gauge for monitoring pressures. The pressure tap is located under the main manifold. The gauge reads from 34450 kPa ( 0 to 5000 psi).

(44) TP16 Pressure Gauge: An 8T-0851 Analog Gauge for monitoring pressures. The pressure tap is located under the main manifold. The gauge reads from 0 to 13780 kPa (0 to 2000 psi).

(45) Lube Pressure Gauge: An 8T-0848 Analog Gauge for monitoring the pressure for external lubrication to the test unit. The gauge reads from 0 to 415 kPa (0 to 60 psi).

(46) XP1 Pressure Gauge: 8T-0850 Analog Gauge for monitoring pressure inside the secondary heat exchanger during closed loop pump testing or simulating cooler loop. The pressure tap is internal. The gauge reads from 0 to 4135 kPa (0 to 600 psi).

(47) E-Stop Activated Indicator Light: A red light that indicates power is not activated to the electronic controls. The light is activated if a malfunction has occurred such as over speed or a power failure.

(48) E-Stop Reset: Used to reset the electronics and activates the power to the electronics. Upon reset, the E-Stop indicator light will not be on if the malfunction has been corrected and all controls have been returned to start up position.

(49) Main Pump On-Off Switch: Controls the electronics to activate or deactivate the main pump.

(50) Main Pump Displacement Potentiometer: Controls the electronics of the main pump. This control allows the operator to control the maximum displacement of the pump. The output of the main pump is variable from 0 to 375 lpm (0 to 99 gpm).

(51) Auxiliary Pump On-Off Switch: Controls the electronics to activate or deactivate the auxiliary pump.

(52) Auxiliary Pump Displacement Potentiometer: Controls the electronics of the auxiliary pump. This control allows the operator to control the maximum displacement of the pump. The output of the pump is variable from 0 to 208 lpm (0 to 55 gpm).

(53) Motor Direction Selection Switch: Controls the direction of the drive motor for testing components. CCW indicates counter clockwise. CW indicates clockwise. (Looking in towards the test bench.)

(54) Secondary Motor Stop-Run Switch: Allows electronic control of fluid motor system.

(55) Displacement (Disp.) Motor Test, Speed: Controls mode of fluid motor operation. Displacement (Disp.) Mode allows for total manual control of both the pump and secondary motor displacement, Motor Test. Mode allows for test bench to function as a load source for dynamic fluid motor testing. Speed Mode enables test bench drive shaft output to become load sensitive and correct output speed to compensate for load variations in the test component.

(56) Motor Displacement: Electronically controls displacement of fluid motor in displacement mode.

(57) Motor Speed Potentiometer: Electronically controls speed of output shaft in speed mode.

(58) Emergency Stop Button Switch: Activates all controls to null position; also activates E-Stop indicator light.

(59) Control Power Switch and Indicator Light, Pull On-Push Off: Activates all control circuits. (The indicator is green.)

(60) Motor Switch and Indicator Light: Pull On-Push Off: Starts main electric motor. (The indicator is green.)

(61) Sump Pump Switch, Manual-Off-Auto: Starts sump pump in manual or automatic, controlled by float switches in automatic.

(62) Sump Motor Indicator Light, Push To Test: Indicates sump pump running. (The indicator light is green.)

(63) Sump Filter Indicator Light, Push to Test: Indicates filter dirty. All other filter lights function in a similar manner. (The indicator light is red.)

Note: For the location of the sump, super charge pump, pump control, motor control, regenerative, return, auxiliary charge, and main charge filters, refer to the topic entitled Maintenance in this publication.

(64) Reservoir Heater. Switch and Indicator Light, Pull On-Push Off: Turns on the reservoir heater and sump pump, which then becomes thermostatically controlled. (The indicator light is green.)

(65) Reservoir Heater. Activated Indicator Light, Push To Test: Indicates heater status (ON). (The Indicator light is green.)

(66) Reservoir Overfill Indicator Light, Push to Test: Indicates reservoir over filled. The sump system will shut down.

(67) Circulation Filter Indicator Light: Push to Test: Indicates dirty kidney loop filter. (The indicator light is red.)

(68) Super Charge Pump Filter Indicator Light: Push To Test: Indicates suction filter is dirty in super charge system. (The indicator light is red.)

(69) Pump Control: (Main Charge Pump Pressure) Filter Indicator Light, Push to Test: Indicates pressure filter is dirty in pump control system. (The indicator is red.)

(70) Motor Control Filter Indicator Light, Push To Test: Indicates servo filter is dirty in motor control system. (The indicator light is red.)

(71) Loop Filter Indicator Light: Push to Test: Indicates filter is dirty in closed loop system.(The indicator light is red.)

(72) Return Filter Indicator Light, Push to Test: Indicates filter is dirty in the tank return system. (The indicator light is red.)

(73) Auxiliary Charge Filter Indicator Light, Push To Test: Indicates suction filter is dirty in main/auxiliary charge system. (The indicator light is red.)

(74) Main Charge Filter Indicator Light, Push to Test: Indicates pressure filter dirty in supercharge system. (The indicator light is red.)

(75) Low Oil Level Indicator Light, Push to Test: Indicates main reservoir is low on oil. (The indicator light is red.)

(76) Main Pump Charge PR. Indicator Light, Push to Test: Indicates inlet pressure to main and auxiliary pumps is sufficient. (The indicator light is green.)

Connection Panel (Upper)

Illustration 5	g02531736

The manifold has a number of hydraulic circuits used to test components. The circuits are designated as loops.

The F3 loop consists of four 1-1/4 inch quick disconnect ports, one 3/8 inch quick disconnect port and one adjustable flow control valve on the front of the manifold. Flow is monitored on flowmeter F3. Pressure is monitored on gauges G5 and G6. Margin pressure is monitored on G11, and pressure in the circuit is controlled by load control C6.

1. Pump Test Flow Limiter Control - C8: An adjustable flow control for controlling the volume of oil through the F3 loop, when testing load sensing pumps.

2. Flowmeter F3 Loop In - I1: An inlet port in the loop, oil going into the manifold at this point goes directly to the flowmeter.

3. Pump Test Loop and Flowmeter In-12: An inlet port in the F3 loop, oil going in goes through the Pump Test Flow Limiter Control C8 before going to the flowmeter. This port is used to test load sensing pumps.

4. Pump Test Loop and Flowmeter F3 Out E1: An outlet port in the F3 loop, oil going out has been pressure controlled by a relief valve which is pilot controlled by Load Control C6.

5. Flowmeter F3 Out - E2: An outlet port in the F3 loop, oil going out at this point is not pressure controlled but has gone through the F3 Flowmeter.

6. Pump Test Margin Pressure Sense Line In - I4: A pressure sense line port which will be used in setting load sensing pumps.

   The F4 loop consists of three 1 1/4 inch quick disconnect ports. Flow is monitored on flowmeter F4, pressure is monitored on Gauge G7, and pressure in the circuit is controlled by load control C7.

7. Pump/Transmission Flowmeter F4 Loop In - I3: An inlet port, oil going into the manifold at this point goes directly to the F4 flowmeter.

8. Pump Test And Flowmeter F4 Out - E3: An outlet port, oil going out is pressure controlled by a relief valve which is pilot controlled by Load Control C7.

9. Flowmeter F4 Out - E4: An outlet port, oil going out at this point is not pressure controlled but has gone through the F4 flowmeter.

   Other ports on the manifold:

10. Main Pump Supply Out - E5: An outlet port in the hydrostatic loop, it is used only for checking out the main pump.

11. Pump Test/Flowmeter FI Closed Circuit Loop In - I7 and I8: Inlet ports for testing closed circuit pumps. Oil going in, at this point goes through the F1 flowmeter and is routed to port E7. Oil can then be sent to any of the loadable flow meter loops.

12. Return to Tank - I5 and I9: Inlet Ports: Oil going in at these points returns to the main reservoir.

    The F2 loop consists of two 1 - 1/4 inch quick disconnect ports. Flow is monitored on the F2 Flowmeter and pressure is monitored on Gauges G3 and G4. It also is the outlet for the auxiliary pump.

13. Auxiliary Pump Supply Flowmeter F2 Out E6: An outlet port in the F2 loop, this port supplies oil for running transmissions, fluid motors, and relief valves. The volume and pressure are determined by the auxiliary pump circuit. It is also an outlet port if the F2 flowmeter loop is used as a flowmeter loop.

14. Flowmeter F2 Loop In - I10: An inlet port in the F2 flowmeter loop, oil going in at this point, goes through the F2 flowmeter. This circuit cannot be used to load pumps.

15. Bearing Lube Control - C9: A needle valve used to control oil flow to bearings on test fixtures.

16. Bearing Lube Supply - S1: An outlet port for supplying oil to bearings on test fixtures. The oil flow is controlled by Bearing Lube Control C9.

17. Main Pump Blocking Valve - V1: A cartridge valve used to block the oil from the main pump. The valve is used to isolate the main pump.

18. Main Pump Test Port - S5: An outlet port to check the main pump pressure and flow.

19. High Pressure Supply, 0 to 7000 psi - S2: An outlet supply of 13 lpm (3.5 gpm) from 0 to 49600 kPa (0 to 7000 psi). The pressure is controlled by the Hydraulic Pump Pressure Control Valve C3 and the pressure can be read on the High Pressure Gauge G9 This supply oil can be used to test high-pressure relief valves and controlling pumps.

20. Pump Control Supply, 0 to 450 psi - S3: An outlet supply of 17 lpm (4.5 gpm) from 0 to 3100 kPa (0 to 450 psi). The pressure is controlled by Auxiliary Pressure Control Valve C1 and read on the Auxiliary Pressure Gauge G8. It supplies oil for controlling pumps.

21. Super Charge Outlet Pressure - S6: An outlet 0 to 3450 kPa (0 to 500 psi) port from the super charge pump. It is controlled by Super Charge Pressure Control C5.

22. Low Pressure in Closed Circuit - I11: An inlet port for oil being returned to closed circuit pump loop.

23. High Pressure Out Closed Circuit - E7: An outlet port from flow meter loop F1.

Connection Panel (Lower)

Illustration 6	g02541439

1. Hydraulic Motor Lift Actuator: A four way valve for raising and lowering the drive shaft. To lift the drive shaft, the pressure on the supercharge pump circuit must be increased by Control Valve C5 to 2410 kPa (350 psi). Also, before moving the drive shaft, the side rail lock bolts must be loosened.

   Note: Make sure that the side rail lock bolts have been tightened before running the test component.

2. Flowmeter F5: A 0.1 to 30.0 gpm digital flowmeter. Oil going into the unit goes through a 1 inch quick disconnect, through the flowmeter, and back to the work table sump. This flowmeter is primarily used for checking case drains on pumps and motors.

3. Flowmeter F6: A 0.5 to 5.0 gpm flowmeter. Oil going into the unit goes through a 1 inch quick disconnect, through the flowmeter, and back to the work table sump. This flowmeter is primarily used for checking case drains on pumps and motors.

4. Component Oil Supply 3 & 4 Inch Lines - S4: An outlet port for supplying oil to test components. There is approximately a four foot head of oil pressure at this port.

5. --

6. TP1: Read at Gauge TP1.

7. TP2: Read at Gauge TP2.

8. TP3: Read at Gauge TP3.

9. TP4: Read at Gauge TP4.

10. TP5: Read at Gauge TP5.

11. TP6: Read at Gauge TP6.

12. TP7: Read at Gauge TP7.

13. TP8: Read at Gauge TP8.

14. TP9: Read at Gauge TP9.

15. TP10: Read at Gauge TP10.

16. TP11: Read at Gauge TP11.

17. TP12: Read at Gauge TP12.

18. TP13: Read at Gauge TP13.

19. TP14: Read at Gauge TP14.

20. TP15: Read at Gauge TP15.

21. TP16: Read at Gauge TP16.

22. Recirculation Filter Drain

23. Sump Filter Drain

24. "IN" Connection for Secondary Heat Exchanger (1" NPT)

25. "OUT" Connection for Secondary Heat Exhanger (1" NPT)

26. Auxiliary Pressure Inlet: A port that allows oil to enter the high pressure closed loop filters and exit through port E7. This provides a safe effective way of filtering the output of gear pumps (during teeth cutting procedures) before the oil enters a loading circuit. By doing this, the risk of metal debris contaminating/damaging the test center's components is greatly minimized.

Initial Start-Up

Note: The main electrical disconnect should be OFF at this time.

Sump/Circulation Pump Rotation Check

Illustration 7	g02541756
Sump Pump (mounted to side of sump on models equipped with standard heavy sump.)

Note: The electric motor starter came supplied and pre-wired from the factory. The direction of rotation of all electric motors was correct when tested, but should be checked. If rotation of any of the motors is not correct, confirm all motor rotation directions before changing phase of incoming power.

Note: Do not let the sump pump run dry.

1. Begin filling the sump with oil. This should take approximately 660 L (75 gal).

2. Once the sump is full, turn ON the main electrical disconnect. Activate the CONTROL POWER switch by pulling OUT. Jog the pump by turning the Sump Pump control switch to manual.

3. Observe sump pump rotation at the shaft. Remove the debris cover on the sump motor. The shaft should turn clockwise as viewed from the top of the pump towards the impeller housing. If rotation is not correct, turn off main power and switch any two of the three wires in the incoming 3-phase current at the main electric motor starter.

4. Open the ball valve on the Circulation Pump inlet on the bottom of the main reservoir.

5. Jog the Circulation Pump by pulling the Reservoir Heater switch to the ON position momentarily. The shaft should turn clockwise as viewed from the rear of the pump towards the impeller housing.

6. Once the correct rotation has been determined, turn the sump pump switch to Manual and visually verify pump flow. Replace debris cover.

Illustration 8	g02541784

Check Main Motor Rotation

1. Turn the Component Oil Supply - S4 valve (4) to the closed position.

2. Place approximately 720 L (250 gal) of oil into the main tank. This should place the level of the tank approximately 3/4 of the way up in the Sight Gauge located on the end of the tank.

3. Push in CONTROL POWER switch. SUMP PUMP CONTROL must be in the OFF position.

4. Do not turn all pressure adjustment valves on the gauge panel all the way out (counterclockwise). Turn them out just far enough to ensure that they are at a minimum. Forcing these valves too far counterclockwise may damage the internal sealing components, causing leaks from the valve stems.

5. Verify push-pull controls (Control Power, Motor, and Reservoir Heater) on the gauge panel are pushed IN.

6. Verify all switches on the gauge panel are turned to the OFF position.

7. Remove cover plate from Auxiliary pump/motor housing. This is to observe Main Motor shaft rotation.
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   Illustration 9	g02541796

8. Turn ON the main electric disconnect switch.

9. Activate control power to the test stand by pulling OUT the Control Power switch. Do NOT activate the Motor switch at this time.

10. Verify all flowmeter, torquemeter, and RPM displays are functioning. Check all push-to-test indicator lights for operation.

11. The E-Stop Reset light will be lit at this time. Push the E-Stop Reset button until indicator light is off.

12. The Hydraulic Test Center is now ready for the main electric motor to be jogged.

    Note: The electric motor starter came supplied and pre-wired from the factory. The direction of rotation of all electric motors was correct when tested, but should be checked.

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    Illustration 10	g02542798

13. Jog the main electric motor by pulling out and pushing in the Motor Switch on the electric control panel momentarily. The main electric motor shaft should rotate in a counterclockwise direction when viewed from the Auxiliary pump end.

    Note: Always disconnect main electrical source and lockout before doing any work on the electrical system. Improper maintenance can be dangerous, resulting in possible injury or death.

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    Illustration 11	g02542836

14. If it does not, you must do two things: Switch any two of the three wires on the incoming 3-phase current at location (A). Now recheck the rotation of the main electric motor to verify that they are correct. Jog the main electric motor. This is so the system will pick up its prime. It is important that when starting the main motor for the first time that it be jogged until there is a noticeable difference in the sound of the pumps. It will make various noises as air is forced out of the system. After the air is purged from the system, pull the MOTOR Switch and let the motor come up to full speed.

Initial Operation Check

Start the main motor. Make sure that all switches are in the OFF position. All control potentiometers are turned fully counterclockwise. All pressure control valves are out to minimum load position. The Drive Shaft should not be installed at this time. Make sure that all components are clear of the drive shaft guard area. Once main motor is on, check for the following:

Super Charge Pressure G10 rises to 1030 kPa (180 psi) maximum. The Main Charge Pressure light should be illuminated. If it isn't slowly increase pressure control valve (C5) until the light goes off and verify that the supercharge pressure is within the acceptable range.

The E-STOP light is OFF. If not, push in the E-STOP reset.

Turn the SECONDARY MOTOR selector switch to the RUN position.

Turn the MOTOR DIRECTION switch to CLOCKWISE.

Check the DISP, MOTOR TEST, SPEED pot for the DISP position.

Turn the MAIN PUMP switch to the ON position.

Slowly turn the MAIN PUMP DISPLACEMENT pot clockwise, to obtain flow out of the main pump. The Secondary Motor will begin to rotate clockwise as viewed from the front of the machine. Allow Secondary Motor to rotate for approximately 2-3 minutes to remove air from the hydrostatic system.

Slowly turn the SECONDARY MOTOR DISPLACEMENT pot clockwise. The SECONDARY Motor will begin to increase in speed.

Turn the SECONDARY MOTOR DISPLACEMENT pot counterclockwise to zero.

Turn the MAIN PUMP DISPLACEMENT pot counterclockwise to zero.

Turn the MOTOR DIRECTION switch to COUNTERCLOCKWISE.

Slowly turn the MAIN PUMP DISPLACEMENT pot clockwise to obtain flow out of the main pump The Secondary Motor will begin to rotate counterclockwise as viewed from the front of the machine. Allow Secondary Motor to rotate for approximately 2-3 minutes to remove air from the hydrostatic system.

Slowly turn the SECONDARY MOTOR DISPLACEMENT pot clockwise. The Secondary Motor will begin to increase in speed.

Turn the SECONDARY MOTOR DISPLACEMENT pot counterclockwise to zero.

Turn the MAIN PUMP DISPLACEMENT pot counterclockwise to zero.

Turn the MAIN PUMP ON-OFF switch to the OFF position. Turn the SECONDARY MOTOR switch to the stop position. Push Off the Main Motor. The main pump and secondary motor are now set up electronically in an operating condition.

Illustration 12	g02542899
Main Pump Displacement Pot

Illustration 13	g02542900
Auxiliary Pump Displacement Pot

Auxiliary Pump Check

At this time, connect a hose from the outlet of the Auxiliary Pump Outlet (E6) and connect the other end to one of the Return To Tank ports (I5 or I9).

Pull the Main Motor switch to ON.

Turn the AUXILIARY PUMP switch to the ON position.

Turn the AUXILIARY PUMP DISPLACEMENT pot clockwise. This will increase the displacement. Oil should flow through the auxiliary pump F2 Flowmeter, outlet port E6, to which hose (13) has been connected. Maximum flow of 57gpm should be observed on F2 Flowmeter.

Note: If no flow is generated, increase the pressure setting with the auxiliary pump control C4. This will ensure that the auxiliary pump is functioning properly.

Turn the AUXILIARY PUMP DISPLACEMENT pot to ZERO. Back out the AUXILIARY PUMP control C4 and turn the AUXILIARY PUMP switch to OFF. Push in MOTOR switch to shut off the electric motor.

Remove hoses from E6 and I5 or I9.

Auxiliary Pressure Control Circuit Check

Pull the Main Motor switch to ON.

Raise the pressure on auxiliary control C1. The pressure should be variable to 310 kPa (450 psi) Read the pressure on Auxiliary Gauge G8. Decrease the pressure to the minimum setting.

High Pump Pressure Check

Increase the high-pressure circuit by turning the high-pressure control valve C3 clockwise. The pressure should be variable from 0 to 49600 kPa (7000 psi) as indicated on G9. Decrease the pressure to zero.

Super Charge Pump Circuit Check

Increase the high-pressure circuit by turning the high-pressure control valve C5 in a clockwise direction. The pressure should vary between 1035 kPa (150 psi) and 3445 KPa (500 psi) as read on Gauge G10. Decrease the pressure by rotating the control valve counterclockwise. The pressure should decrease to approximately 1035 kPa (150 psi).

Heat Exchanger Adjustment

Illustration 14	g02542937
Main Heat Exchanger

Check and adjust heat exchanger (1) now and during the first component test on the stand. The operating temperature of the heat exchanger can be adjusted by turning the adjustment screw on the Water Modulating Valve (2). Adjustments were made during factory run-out procedures, but due to probable differences in the supply water's flow and temperature, a readjustment may have to be made. Observe the MAIN RESERVOIR TEMPERATURE Gauge located on the gauge panel during operation. With proper heat exchanger adjustment, the reservoir temperature will remain in the 49° C (120° F) to 52° C (125° F) zone. Only for brief occasions during long, involved tests will the temperature reach the 60° C (140° F). This is acceptable only for short durations while a test is being conducted. By turning the adjustment lug clockwise, the valve will allow water to flow through the heat exchanger at a lower oil temperature. Counterclockwise will allow the oil to get hotter before it opens. It is recommended the valve be opened fully upon start-up to find the proper setting for the specific environmental conditions.

Main Reservoir Heater/Circulation System

The test center is provided with a 12.5 kW (16.76 hp) immersion heater integral to the main reservoir. If needed, the oil may be heated to a pre-set temperature for immediate testing of components requiring oil of a specific viscosity. The thermostat is located on the main reservoir inside the service area. It is covered with a metal cap that must be removed for adjustment. Once the thermostat has been set, pull the RESERVOIR HEATER switch to the ON position.

Illustration 15	g02542978
Heater and Thermostat

The heater will begin to warm the oil to the specified temperature. The circulation pump will move oil across the heater element to prevent the oil from burning at the element. Once the oil has reached the specified temperature, the heater will shut off but the circulation pump will continue to operate.

It is recommended the heater only be used during periods when personnel can monitor oil temperature.

The circulation system can also function as a kidney loop filtration system. If the reservoir tank heater is not required, the thermostat may be turned down to minimum. The RESERVOIR HEATER switch is then pulled ON and the oil will then circulate through the 3 micron CIRCULATION FILTER located next to the thermostat. This will allow the oil to be purified during idle periods. Another benefit of this system is the operation of the pump will warm the oil to approximately 24° C (100° F). This will allow the oil to be warmed without monitoring during periods when personnel are not available to monitor oil temperature.

The Hydrostatic System

The hydrostatic system consists of the main electric motor, the hydraulic pumps, the hydraulic motor, the hydrostatic reservoir, and various controls. Simply stated, by operating a few controls, you will be able to control the output speed of the hydraulic motor anywhere within its range.

Illustration 16	g02542997
Main Electric Motor

The main electric motor is the prime mover. It provides input power to the hydrostatic system as well as the other hydraulic functions of the test bench. The size of the electric motor determines the maximum horsepower of the test center.

Illustration 17	g02543036
Main Pump

The main pump (1) driven by the electric motor, provides pressurized fluid to the secondary fluid motor. Displacement is electronically controlled and pressure is adjustable from 0 - 43400 kPa (0 - 6000 psi) from the Hydrostatic Loop Pressure Control (C2) on the gauge panel. Maximum pressure is controlled by crossover relief valve cartridges mounted in the pump.

Mounted to the rear of the main pump is the supercharge pump (2). This pump provides pressurized oil to hydraulic components in the test bench to eliminate cavitation and provide flow for the cooling system. Oil from this pump is constantly circulated when the main electric motor is ON and is filtered after it passes through the heat exchanger then back to the tank. Oil from the supercharge pump can also be used as a supplemental oil source for some test components.

Located on top of the main pump is the main pump displacement feedback pot (3). This pot is a feedback device for the digital speed control to measure displacement of the main pump when the test bench is in SPEED MODE.

The auxiliary pump (4), driven on the other end of the electric motor, provides pressurized oil to test components. The displacement is also electrically controlled and pressure is adjustable from 0 - 43400 kPa (0 - 6000 psi).

Illustration 18	g02543079
Auxiliary Pump

Mounted to the rear of the auxiliary pump is the R4 radial piston pump (5). Output from this pump is used for two purposes. Half of the flow is used to provide a preset control pressure to the secondary motor servo. The other half is used to provide controlled, pressurized oil for test components requiring a high-pressure signal source.

The secondary motor (6) is a fluid motor driven by the main pump. It provides output power to drive test components. Connected to the output shaft is an inline torque transducer (not shown) that measures drive shaft torque being transmitted to the test component. This torque value is read on the gauge panel.

The LVDT (7) is a sensor that measures secondary motor displacement. This can be monitored on the gauge panel. It also works as a feedback device for the digital speed control when the test center is in SPEED MODE.

Illustration 19	g02543116
Secondary Motor

The servo (8) controls the displacement of the secondary motor.

The tach generator (9), is used by the digital speed controller as a feedback device to provide a reference signal for output RPM when the test center is in SPEED MODE.

The Sump Pump System

The sump pump will return oil from the work support sump to the main reservoir. The control switch, labeled SUMP PUMP, is located in the row of electrical controls. In the automatic position it will pump excess oil as necessary, but will always leave 660 L (100 gal)of oil in the work support sump. In the manual position it will pump until turned off.

Oil level in the sump is controlled by a high-level float switch. When oil is at normal level, the switch is de-activated. Once the oil level begins to rise, the switch will be activated. The oil will then be pumped back to the main reservoir. At this time, the sump pump is controlled by an adjustable timer which will eventually shut off the pump.

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NOTICE
DO NOT run the sump pump dry. It is preferred that the switch of the sump pump is left in automatic during testing and when idle with the control power ON. Manual position should be used for filling the reservoir or for maintenance purposes only.

Fluid Conditioners

Fluid conditioners on the Hydraulic Test Center are the filters and the heat exchanger. These are not highly obvious controls in the system because they operate automatically most of the time. Attention to them is not normally required between regular maintenance. However, their operation is nevertheless invaluable to the performance of the test stand and should be understood.

Filters

There are several filters throughout the test center. These filters will maintain an acceptable level of oil cleanliness in the system during operation, but as they do their job, they will become dirty, at which time the filter elements must be changed.

A FILTER NEEDS CLEANING indicator, located at the bottom of the instrument panel, will come on to indicate a dirty filter. (See the Oil Filters and Strainers heading in the MAINTENANCE section of this publication for instructions on changing elements).

Heat Exchanger

The heat exchanger used on this Hydraulic Test Center is the oil-to-water heat exchanger that cools hot oil by passing water through tubes in the oil. The effectiveness of the heat exchanger depends on the temperature of the water being used for cooling and the condition of the heat exchanger itself. (See the Heat Exchanger heading in the MAINTENANCE section of this publication for maintenance instructions.) The operation of the heat exchanger is automatic. A thermostatically controlled water regulating valve, located on the outlet side, will operate the heat exchanger only when necessary to maintain proper oil temperature in the system.

Operation

To start the test center for day-to-day operation, pull OUT the CONTROL POWER electric switch. This provides 110 Volt power to the instrument control circuit. It is recommended the control power be left on and the SUMP PUMP be left in AUTO to prevent the sump from overfilling if the S4 Suction Supply valve is inadvertently opened or if a test component is left installed on the Work Support Sump.

Check that all valves, and controls are adjusted as you want, preferably in the neutral, off, or closed conditions. Then, pull OUT the MOTOR electric switch to start the main electric motor.

Testing

This section will outline testing procedures in general, as they will be performed on the Cat 1U-9400 Series Hydraulic Test Center. Specific instructions and test specifications for any particular test component will have to come from that component manufacturer. When in doubt, contact the particular manufacturer for missing specifications or for clarification.

Transmissions

Note: Use NEHT5000 Bench Testing Hydraulic Components. Tooling and test procedures are specified in the instructions. The purpose of the transmission test is to insure that the transmission will function properly in the vehicle. The best test is to rotate the transmission, as if it were being driven by an engine. By rotating the transmission, pressure settings can be adjusted, shift points can be quickly set, flows can be checked, and unacceptable operating conditions such as leakage, excessive noise, and vibration can be identified.

Note: The Hydraulic Test Center will not act as a load bank for transmissions. Clutch slippage can only be verified in the vehicle. The Hydraulic Test Center is capable of producing many conditions which simulate vehicle operation. Basically, the test cell will perform the following functions:

Testing

1. The main drive will rotate the transmission in the required direction at the desired speed.

2. The Auxiliary Pump Supply will provide regulated oil flow at pressure to the control valve and clutch system on the transmission. The Auxiliary Pump Supply takes the place of the vehicle charge pump where one is not integral to the transmission itself. The supercharge supply can be used to augment oil supply for components with multiple inlet requirements.

3. Suction Supply will provide a gravity fed oil supply for transmissions with integral charge pumps.

4. The flowmeters provide a means to monitor the amount of flow and leakage in a system.

5. Pressure Gauges are used to monitor transmission internal pressures.

6. When the transmission is rotating and provided with the proper oil supply, it will be possible to determine the clutch pressures, the relief valve settings, and any valve functions. It is important to note two things at this point: First, the Auxiliary Pump Supply System must be adjusted to the exact flow the transmission would receive in the vehicle. This does not mean that the transmission would receive 195 lpm (50 gpm) if the vehicle has a 195 lpm (50 gpm)pump because normally the pump supplies oil to other functions as well as to the transmission. The exact flow to the transmission should be determined from the manufacturer of the vehicle. If too much flow is supplied to the transmission during test, it will be impossible to determine clutch pack leakage and incorrect test results will be obtained. Second, if the transmission being tested has a relief valve as an integral part of the transmission, the Auxiliary Pump Supply pressure must be established at 689 kPa (100 psi) ABOVE the relief valve setting of the transmission. If not, it would be impossible to determine which relief valve is controlling the pressure. If the transmission does not have a relief valve, then the Auxiliary Pump Supply pressure must be set at the proper pressure to protect the transmission.

Illustration 20	g02543157

Mounting a Transmission

Mounting a transmission on the test stand consists of three steps.

1. POSITIONING: With the transmission hanging on a chain from an overhead hoist, position the unit so that the input shaft on the transmission and output shaft on the test stand line up horizontally, as closely as possible.

   The test stand output shaft may be adjusted up or down so that the two shafts may be closely positioned vertically as well.

2. LEVELING: A secure, level base should be provided by the use of universal mounting adapters, coupled with special adapters for particular transmissions. Position one support bar as far forward and one as far back as possible under the transmission. Place the spacers in the slots of the support bar so that the transmission has a flat base to securely rest on, or is supported by clevis adapters. The transmission is bolted down on many applications with special adapters. Connect the drive shaft at this time.

3. SECURING: Two chains with load binders can be used to secure the transmission to the work support sump. The chains may be attached to the eyebolts in the support bars. The chains then pass across the transmission, are looped around the lifting eyes and the slack taken up by the load binders. The load binders should be placed on opposite sides. This will keep the mounting snug and secure and will prevent the transmission case from rotating during violent shifts. Recheck alignment of the drive shaft. Install the drive shaft guard.

Driving a Transmission

There are two drive arrangements on transmissions: remote type or direct mount.

1. REMOTE TYPE: The remote mounted transmission is normally connected to the engine through a drive shaft. Therefore, it is necessary only to connect the transmission to the test stand output shaft with the drive shaft and suitable flanges.

2. DIRECT MOUNT: On transmissions with torque converters that bolt directly to the engine, it is necessary to bolt on the proper drive adapter to drive and support the torque converter. After this has been done, the transmission will be connected to the test stand output shaft in the same manner as the remote type. All necessary mounting, drive, and accessory hardware needed to accomplish complete testing of many types of transmissions can be supplied by Caterpillar Inc.

Pump Testing

Note: Use NEHT5000 Bench Testing Hydraulic Components. Tooling and test procedures will be specified in the instruction.

Rebuilt pumps should be tested to ensure that the pumping capacity is at an acceptable level. Also, testing under loaded conditions is necessary to assure that the reassembly has been properly made and that there are no shaft, seal, or cover leaks.

Pump condition (pumping efficiency) can be determined by observing the amount of oil leakage that occurs within the unit. Some leakage takes place in all new pumps from the high pressure to the low-pressure side.

In vane pumps, this is dependent upon the amount of clearance between the rotor slots and vanes, between the end plates and rotor vanes, and the condition of contact between the vane tips and the ring surface.

In gear pumps, it is dependent upon gear match or clearance between gears, fit of gears to side plates, and fit of gears to housing.

In piston pumps, leakage occurs between the pistons and piston barrel, the piston barrel and port plates, and the port plates and housing. This is called case drain leakage.

It is standard practice to compare pump flow at 689 kPa (100 psi) to pump flow at 6890 kPa (1000 psi) while maintaining a constant rpm. Pump losses from leakage are directly affected by pressure. Therefore, this method proves quite useful in determining pump condition.

In testing a pump, the pump is normally rotated at a given rpm (usually 1200 or 1800) at 689 kPa (100 psi) back-pressure on the pressure port. The resulting flow is the performance base of the pump. After recording the base flow, the pressure is increased to 6890 kPa (1000 psi) while the speed is maintained. The decreased flow at the higher pressure is expressed as a percentage loss, indicating the pump efficiency:

% Loss = flow rate @ 100 psi minus flow rate @ 1000 psi divided by flow rate @ 100 psi.

For example:

a pump that pumps 50 gpm at 100 psi and 48 gpm at 1000 psi shows a 4% loss. 4% = 50 minus 48 divided by 50 times 100

Acceptable losses vary widely among various types and sizes of pumps and various manufacturers. For example, piston pumps are generally more efficient than either vane or gear pumps. Also small pumps exhibit a greater percentage loss than large pumps. Every effort should be made to obtain performance information from the pump or equipment manufacturer. But, should this information be unavailable, a rule of thumb is; a piston pump that loses no more than 10% base flow at 6890 kPa (1000 psi) or a gear or vane pump that loses no more than 20% are acceptable for return to service.

Consideration should be given to the type of machine or application in which the pump will work. A high production or high cycling machine would probably require a pump with low loss, while a machine that works intermittently could tolerate higher losses.

Consideration must also be given to the temperature at which the pump normally operates. Pumping losses increase with rising temperature, due to the change in oil viscosity. The thinner the oil becomes, the easier it is to circulate within the internal pump components. Flow rate change can be expressed by another rule of thumb; pump capacity will decrease approximately 0.5 gpm for every 10°F of temperature rise from 120°F to 180°F. Double this value if flow from two sections of a pump are combined.

Connections to Pump

Illustration 21	g02543177

Connections to a typical pump consist of a line to the pump suction port and a line from the pump outlet port (two ports if a two section pump). A piston pump will also likely have a case drain line and a pressure tap line connected. The suction line should always be connected at the lowest possible point.

1. To test the typical gear or vane pump, open the pump suction valve on the Hydraulic Test Center.

2. The hose coming from the pump outlet port should be directed to the work support sump at first for priming and rotation check. (Some oil will flow through the pump at this point, providing lubrication.)

3. Jog the pump at low speed (less than 600 rpm) until it is primed. (Be sure that rotation is correct).

4. When the pump is primed and oil flows from the loose pressure line, connect the line to Test Circuit 1 or 2 depending on the style and capacity of the pump.

5. The test should proceed according to the pump or vehicle manufacturer's test specifications.

6. To test the typical piston pump, always fill the case with oil.

Hydraulic Motors

Illustration 22	g02543179

Hydraulic motors can be tested on the Hydraulic Test Center if they are of the type that can be tested as if they were pumps. Testing will proceed according to the hydraulic motor or vehicle manufacturer's test specification.

1. Install the fluid motor on the test bench, using a test procedure if one is available. If there are no specifications available, use the Service Manual Test and Adjust Procedure.

2. Fill the case with oil if testing a piston style fluid motor.

3. Connect a hose from the Auxiliary Pump Supply Flowmeter F2 Out, E6, to the inlet side of fluid motor. On most fluid motors, either port can be used.

4. Connect a hose from the outlet of the fluid motor to Return To Tank In, I5 or I9.

5. Connect a hose from the case drain to one of the flowmeter loops, F5 or F6, on the bench. If flow exceeds the rating of these flow meters, connect hose to either F3 or F4 Flowmeter inlets. Connect a hose from the flowmeter outlet and let the oil run into the sump work table.

6. After all proper connections have been made, turn on the Hydraulic Test Center.

7. Select CCW or CW on the MOTOR DIRECTION SWITCH.

8. Select MOTOR TEST on the DISP, MOTOR TEST, SPEED switch.

9. Turn the MAIN PUMP and SECONDARY MOTOR switches to RUN. Do not turn the MAIN PUMP or SECONDARY MOTOR displacement pots.

   The MOTOR DISPLACEMENT meter will go to full displacement.

   Note: Secondary Motor displacement can be seen on Manual Motor Displacement Meter or it can also be observed on the fluid motor manual displacement indicator.

10. Select ON position on the AUXILIARY PUMP ON/OFF switch.

11. Increase pressure on the AUXILIARY PUMP CONTROL, C4, by using displacement and the pressure control. The test motor will start to rotate.

12. If you have not determined direction of rotation, it can now be observed on the drive shaft. If direction is incorrect, Pressure in the Hydrostatic Loop and Test Component Circuit as monitored on Gauge G2 will begin to drop to zero. Turn the AUXILIARY PUMP ON/OFF switch to the OFF position and reverse the motor direction. After the proper direction has been selected, turn the AUXILIARY PUMP OFF/ON SWITCH to the ON position.

    Note: With the test motor rotating, indication of hydrostatic pressure should be observed on the HYDROSTATIC LOOP PRESSURE GAUGE, G2.

13. Pressure and flow from the auxiliary pump can now be increased by using the AUXILIARY PUMP DISPLACEMENT and the AUXILIARY PUMP CIRCUIT CONTROL, C4, to obtain the desired rpm and load.

14. To increase load on the test fluid motor, it will be necessary to increase pressure on HYDROSTATIC LOOP TEST COMPONENT CIRCUIT C2, as this main pump now becomes a fluid motor. Oil will be pumped from the hydrostatic loop at the pressure selected on C2 PRESSURE CONTROLLER. The Hydraulic Test Center's fluid motor now functions as a pump, supplying oil to the hydrostatic loop.

    Note: If the main pump has 15.2 cubic inch displacement per revolution and the test center's fluid motor has 21.7 cubic inch displacement per revolution, the SECONDARY MOTOR POT should be adjusted to 100% only when the test motor speed is to be faster than 1020 RPM. The electric motor rotates the main pump at 1560 rpm. Since the ratio between the pump and fluid motor is 1:1.7 at full displacement, the fluid motor will only go to 1020 rpm. In order to run the test fluid motor above 1020 rpm, the displacement of the fluid motor on the test center will have to be decreased in displacement.

    Example: If the test fluid motor is to be rotated at 1020 rpm the test center fluid motor should be set at 100 percent displacement.

Cylinders

Cylinders can be tested on the Hydraulic Test Center to determine if they operate correctly in respect to leakage, binding, and rod drifting.

1. Place the cylinder on the sump with care taken to ensure that when the rod is fully extended, it will not be damaged or cause damage to any part of the test stand.

2. Connections to the test stand are made by attaching appropriate fittings to the cylinder input and output ports.

3. Connect hydraulic hoses from the Auxiliary Pump Supply on the test stand to the appropriate ports on the cylinder.

4. Cylinder testing consists of alternately directing a flow of oil under pressure to one cylinder port while venting the other in order to check rod extension and retraction. During cylinder rod travel, the system pressure gauge should be observed to determine whether any tight spots occur. With steady oil flow into the cylinder, there should be no appreciable change in pressure.

5. A second test consists of blocking one cylinder port and pressurizing the other, thus trapping pressure in the cylinder. Since the force in the rod end is lower than in the head end of the cylinder, poor piston sealing can be determined by the drift rate of the rod. Oil from the higher pressure side of the cylinder will try to leak past the seals and reach the head end of the cylinder. Any leakage of oil from the rod end to the head end allows the rod to extend.

Maintenance

The Cat Hydraulic Test Center is designed to give years of trouble free service with a minimum of regular maintenance work. Pressurized air can cause personal injury. When using pressurized air for cleaning, wear a protective face shield, protective clothing, and protective shoes. The maximum air pressure must be below 205 kPa (30 psi) for cleaning purposes. Use all cleaning solutions with care.

Oil Filters and Strainers

An adequate amount of clean hydraulic fluid must be maintained in the test stand at all times. Oil is very important to the machine; it performs work and lubricates components. When trouble occurs, it is usually the result of low or dirty oil. Check the level of oil often by looking at the Sight Level Gauge on the left side of the test center. Never operate the test stand unless oil is visible in the gauge. Replenish the oil when needed by dumping the new oil into the work support sump and letting it be pumped on through to the main reservoir.

As the filters on the test center get dirty, it becomes harder for the oil to flow through, thus causing pressure differentials between the inlet and outlet sides of the filters or high vacuums in the suction filters. At about 25 psi (7 in. Hg.) differential, a filter will begin to function inadequately and an indicator light will come on. When one of these lights is ON, it is time to change the filter indicated. After a period of time, hydraulic fluid will need to be changed because it will have accumulated dirt regardless of filter maintenance. This oil change interval depends on the original quality of the oil and the operating conditions. Ideally, oil should be tested periodically in a laboratory. If not possible, clues to oil quality can be found by:

• Feeling the oil for grit and sludge

• Visually inspecting the color of the oil as it changes from its new oil color.

• Smelling the oil to detect chemical change.

Illustration 23	g02543197
Supercharge, Main and Aux Pump Inlet Strainers: 100 mesh Elements (items 73 and 74 on gauge panel illustration)

Illustration 24	g02544996
Tank Return Filters: 4C3054 Elements (Item 72 on gauge panel illustration)

Illustration 25	g02545036
Supercharge Pump Filter: 4C3052 Element (item 68 on gauge panel illustration)

Note: Before changing filter element, close valves at the main, aux, and supercharge pump inlet strainers in order to stop the flow of oil.

Illustration 26	g02545056
Main Charge Pump Filter: 238-6875 (4C5096) Element (item 69 on gauge panel illustration)

Note: Before changing filter element, close valves at the main, aux, and supercharge pump inlet strainers in order to stop the flow of oil.

Illustration 27	g02545060
Closed Loop/Regen Filters: 9U5966 Elements (item 71 on gauge panel illustration)

Illustration 28	g02545256
Sump Return Filter: 205-7381 Element (Item 63 on gauge panel illustration.)

Note: Both Sump and Circulation filters are equipped with canister drains. A hose may be attached to the outlet on the Flow Out and Test Port Panel to drain excess oil into the sump. Close ball valve to prevent oil flow.

Illustration 29	g02545298
Circulation Filter: 205-7380 Element (Item 67 on gauge panel illustration)

Illustration 30	g02545342
Servo Control Filter: 4C5095 Element (Item 70 on gauge panel illustration)

Heat Exchanger

Illustration 31	g02545357

The heat exchanger can become dirty from oil, grease, rust, and scale. It is important to clean the heat exchanger when necessary. Drain the tubes completely by blowing them out with air. Then use a cleaning solvent to remove oil, sludge, and other deposits. Circulate the solvent through the heat exchanger in reverse direction to the normal flows for approximately 15 minutes, after first soaking for about 10 minutes. The exact length of time will depend on the degree of dirt deposit. If the heat exchanger is disassembled for cleaning, use new gaskets upon reassembly. While disassembled, care should be taken while handling the tube bundle to protect the baffle plates and tubes from being bent or damaged. If salt water is used as a cooling medium, zinc pencils (rods) should be used in the heat exchanger on the saltwater side to prevent corrosion of the units. Parts in contact with salt water should be of Admiralty metal, cast iron, or cooper-nickel alloys.

Note: If a closed water cooling system is used, a corrosion preventative should be added. This treatment is effective under normal operating conditions for six months, after which the system should be drained and filled with new solution.

Illustration 32	g02545397
Water Cooling Supply Connections

If the heat exchanger is installed where there is a chance of freezing on shutdown, the water circuit should be completely drained or the correct antifreeze solution should be added.

Electric Motors

Illustration 33	g02545431
Main Electric Motor

Illustration 34	g02545435
Sump Pump Motor (mounted to side of sump on models equipped with standard heavy sump)

Illustration 35	g02545457

Periodically inspect the electric motors for dirt, friction, or vibration. Dust may be blown from inaccessible locations using air. Grease or oil can be wiped up using a petroleum solvent. The main electric motor is equipped with double-shield ball bearings, having sufficient grease to last indefinitely. When the motor is used constantly in a dirty, wet, or corrosive atmosphere, it is advisable to add a quarter ounce of grease per bearing every three months. Use a good quality bearing lubricant grease such as Cat 2S-3230 or equivalent.

Other Operations

Oil Reservoir

Illustration 36	g02545477

The oil level Sight Gauge on the flow port panel of the test stand should be checked daily. Add oil when necessary to keep the level well within the Sight Gauge.

Show/hide table

NOTICE
To avoid damage to the pumps, do not operate the test center when oil cannot be seen in the Sight Level Gauge.

The temperature of the oil in the test stand is indicated by the Temperature Gauge located at the bottom of the instrument panel. If the temperature reaches the 62.7° C (145° F) (approximate), allow the test stand to operate for a short while without performing any work until the heat exchanger has cooled the system. The circulation pump system is used to heat the oil. Pulling ON the RESERVOIR HTR switch will start the circulation pump and activate the heater elements. The heating system is thermostatically controlled and will cycle automatically to maintain a minimum oil temperature of 43.3° C (110° F) in the reservoir. It is good practice when not using the machine to cap all ports and turn all valves, controls, and switches to their OFF or CLOSED positions.

Flow Meters

Illustration 37	g02545565
Flow Meters F1 thru F4

Flowmeters F5 and F6 are located on the front of the lower connection panel. They were described earlier in this instruction.

Illustration 38	g02545583
F5 and F6 Flowmeters

Torque Meter and Drive Shaft

Illustration 39	g02545617
(1) Torque Sensor (2) Carrier Bearing (3) Drive Shaft

Note: Grease carrier bearing (2) every six months.

Illustration 40	g02545696
(1) Torque Sensor

Lift Motor

Illustration 41	g02545859
Hydraulic Lift System

Centrifugal Filters

Illustration 42	g02545864
Centrifugal Filters Replacement Liners 7C8390