Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Wheel Loader

950M (S/N: EMB1-UP; NHL1-UP)

962M (S/N: K881-UP; EJB1-UP)

Introduction

© 2018 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission bay be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.

This Special Instruction includes test procedures for piston pumps. This Special Instruction also provides specifications. The technician should have a good understanding of hydraulic piston pumps. The technician should be educated in the operation of the hydraulic test bench. The test benches in this document are available through the Caterpillar Dealer Service Tools. Gather all necessary tooling before you need to hook up the pump. Some of the required tooling appears in a table at the end of this document. There are many possible variations of tooling that could be used. Not every possible variation can be listed.

For questions or additional information concerning this guideline, submit a feedback form in the Service Information System web site. To address an urgent need, use the following to relay your request to Caterpillar Repair Process Engineering:

• Cat dealer Technical Communicator

• Dealer Solution Network

• Caterpillar Technical Representative

• Knowledge Network (online)

Canceled Part Numbers and Replaced Part Numbers

This document may not include all Canceled part numbers and replaced part numbers. Use NPR on SIS for information about Canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Safety

Illustration 1	g02139237

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Personal injury or death can result from improperly checking for a leak. Always use a board or cardboard when checking for a leak. Escaping air or fluid under pressure, even a pin-hole size leak, can penetrate body tissue causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.

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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.

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Pump test pressures in this guideline may exceed the normal operating range of the hydraulic test hoses utilized when connecting the tested pump to the test bench. However, the order of magnitude of these pressures is significantly below the burst strength of the Caterpillar "XT6" product. High pressure oil can escape through improperly assembled hoses and fittings. High pressure oil can also escape through poorly maintained hoses and fittings. High pressure oil may also leak through hose that has become damaged over the life of the hose due to the pressure levels that occur during test bench operation. Personal injury or death can result from improper hose & fitting inspection or improper hose replacement procedures. Escaping fluid under pressure can penetrate body tissue causing serious injury, and possible death. Thoroughly inspect all testing hoses, fittings, and quick disconnects prior to any testing operation. Check the assembly date tag or hose assembly log date for a hose life indicator. Replace all Test Bench hoses at a minimum of every 2 years or earlier if the hose or fittings appear to be damaged.

Summary

This procedure is specific to the type of pump and the type of control. Refer to the test specifications and the tooling at the end of this document.

Note: A paper copy of this document may not be the latest version. Go to the Service Information System (SIS) to view the latest version.

References

Connections for the Caterpillar Hydraulic Test Center

Illustration 2	g01063311
Connections for the Test Center (1) Flow control for discharge (2) "F3" flow meter inlet (3) "F4" flow meter inlet (4) Oil supply from the auxiliary pump (5) "F3" inlet for the flow meter with flow limiter (6) "F3"outlet for the flow meter with pressure control (7) Load sensing pressure (8) Signal pressure (9) "F4" outlet for the flow meter (10) Return to tank (11) Connections for case drain (12) Oil supply

Illustration 3	g01063312
Control and Gauges for the Test Center (13) Meter for speed and torque (14) Gauge for signal pressure (15) Control for signal pressure (16) Pressure gauge for auxiliary pump (17) Auxiliary pump flow (18) "F3" discharge pressure gauge (19) "F3" discharge flow (20) "F4" discharge pressure gauge (21) "F4" discharge flow (22) Auxiliary pump flow control (23) "F3" margin pressure (24) "F3" Load control for discharge pressure (25) "F4" Load control for discharge pressure

Connections for the Caterpillar Hydraulic Test Bench

Illustration 4	g01063314
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 5	g01093468
Connections for the Test Bench (28) "Flow meter 2" loop (29) "Flow meter 1" loop (30) "Flow meter 2" outlet (31) Signal pressure line (32) "Flow meter 2" inlet (33a) "Flow meter 1" outlet (33b) Auxiliary oil supply outlet (34) Auxiliary oil supply inlet (35) "Flow meter 1" inlet

Illustration 6	g01063316
Control and Gauges for the Test Bench (36) Auxiliary oil supply pressure (37) Signal pressure (38) Control for signal pressure (39) "Flow meter 1" discharge pressure (40) Control for auxiliary oil supply pressure (41) "Flow meter 2" discharge pressure (42) Auxiliary oil supply control (43) "Flow meter 2" discharge flow (44) Discharge flow for auxiliary pump (45) "Flow meter 1" discharge flow (46) "Flow meter 1" load control (47) Speed and direction control (48) "Flow meter 2" load control

Pump Illustrations

Illustration 7	g03680801
Port locations (49) Load sensing pressure port (50a) Case drain port (50b) Case drain port (50c) Case drain port (51) Adjustment screw for margin pressure (52) Adjustment screw for high-pressure cut (53) Electrical connector for on/off solenoid (54) Discharge Port (55) Suction Port

Illustration 8	g03680803
Hydraulic schematic (49) Load sensing pressure port (50a) Case drain port (50b) Case drain port (50c) Case drain port (51) Adjustment screw for margin pressure (52) Adjustment screw for high-pressure cut (53) Electrical connector for on/off solenoid (54) Discharge Port (55) Suction Port

4C-3582 Load Sensing Valve

Illustration 9	g01375820
4C-3582 Load Sensing Valve (56) Outlet port (57) Adjustment for the discharge flow (58) Inlet port (59) High-pressure valve port (60) Adjustment for the discharge port

Illustration 10	g01375822
4C-3582 Load Sensing Valve (57) Adjustment for the discharge flow (58) Inlet port (61) Low-pressure valve port (62) Pressure port for load sensing

Illustration 11	g01375829
Schematic for 4C-3582 Load Sensing Valve (56) Outlet port (57) Adjustment for the discharge flow (58) Inlet port (59) high-pressure valve port (60) Adjustment for the discharge pressure (61) low-pressure valve port (62) Pressure port for load sensing

Illustration 12	g01375830
4C-3582 Load Sensing Valve and 1U-5796 Pressure Differential Gauge (56) Outlet port (57) Adjustment for the discharge flow (58) Inlet port (59) high-pressure valve port (60) Adjustment for the discharge pressure (61) low-pressure valve port (62) Pressure port for load sensing (63) Pressure differential gauge group (64) low-pressure gauge port (65) high-pressure gauge port

Pump Setup

1. Connect a 1 inch high-pressure "XT6" hose from the pump discharge port (54) to inlet port (58) on the 4C-3582 Load Sensing Valve.

2. Connect a 1 inch high-pressure "XT6" hose from outlet port (56) on the 4C-3582 Load Sensing Valve to the flow meter inlet on the test bench.

3. Connect a 1 inch high-pressure hose from the flow meter outlet on the test bench back to the tank.

4. Connect a 6D-7726 Hose Assembly to the pressure port for load sensing (62) on the 4C-3582 Load Sensing Valve. Connect the other end of 6D-7726 Hose Assembly to the pressure port for load sensing (49) on the pump.

   Note: Do not use 1U-5754 Hose Assembly or 1U-5755 Hose Assembly for load sensing signal lines. The flow rate through these hoses will not compensate for the possible leakage through the control valve. Erratic readings will result.

5. Connect the 1U-5796 Pressure Differential Gauge Group (63) to the high-pressure valve port (59) and low-pressure valve port (61) on the 4C-3582 Load Sensing Valve. The port marked "hi" (65) on the 1U-5796 Pressure Differential Gauge Group should be hooked up to the port marked "hi" (59) on the 4C-3582 Load Sensing Valve. The port marked "low" (64) on the 1U-5796 Pressure Differential Gauge Group should be hooked up to the port marked "low" (61) on the 4C-3582 Load Sensing Valve.

   Note: The ports marked "low" (61) and "sense line" (62) on the 4C-3582 Load Sensing Valve are reading the same pressure.

6. Connect a suction line from oil supply to suction port (55) on pump. Purge all air from the suction line. Loosen the suction hose at the pump until oil leaks from the connection. Tighten the suction hose.

7. Fill the pump case with oil. Pour oil directly into a case drain port until the case is full.

8. Connect an in-line flow meter to the highest case drain port (50a). Direct the oil from the in-line flow meter back to the tank.

9. Connect electrical connector for on/off solenoid (53) to an electronic power supply.

10. Do not rotate the pump in the wrong direction. The correct direction of rotation will be stated on the pump. The correct direction of rotation will also be in the test specifications. The direction of rotation is viewed from the input shaft end. Visually check the pump for proper rotation.

Test Procedure

Note: The steps in the procedure correlate with the steps under the "Test Specifications" according to your specific part number.

The contamination level of the hydraulic oil in the test bench should be ISO 16/13 or better. The oil in the test bench should be one of the following.

• SAE 10W at 50 °C (122 °F) or

• Mobil DTE-11 at 46 °C (115 °F)

Illustration 13	g03679666
Pump characteristics (P) Discharge pressure (Q) Discharge flow

Note: For Steps 1, 2, 5, and 6 be sure Adjustment knob for discharge flow (57) and Adjustment for the discharge pressure (60) are completely backed out on the 4C-3582 Load Sensing Valve.

1. Start rotating the pump according to the RPM in Step 1 of the"Test Specifications". Listen for abnormal noise. Verify flow from the pump. Verify that all connections are tight. Check for leaks around shaft seals. Check for leaks around the control valve.

   Run the pump for at least 5 minutes to raise the temperature of the oil and purge the system of air.

2. Slowly increase the input RPM to the value in Step 2 of the"Test Specifications". Record the discharge flow. If the actual flow is less than the value in Step 2 of the "Test Specifications", the pump may not be mechanically feasible. The pump is to be internally inspected.

3. Adjust discharge flow by using the 4C-3582 Load Sensing Valve. Bench circuitry will be used for flow limiting when using a 1U-9400 Test Center. Decrease the discharge flow according to the values in Step 3 of the"Test Specifications". Adjust the discharge pressure according to the values in Step 3 of the"Test Specifications". Adjust the adjustment screw for margin pressure (51) to the value in Step 3 of the"Test Specifications". The margin pressure will be displayed on the 1U-5796 Pressure Differential Gauge (63).

   Note: The margin pressure may change as discharge pressure changes. Adjust margin pressure at Step 3 within operating conditions only.

4. Decrease input speed to the value given in Step 4 of the"Test Specifications". Verify that discharge pressure is equal to the value given in Step 4 of the"Test Specifications". Increase current to the on/off solenoid (53) according to Step 4 of the"Test Specifications". The discharge flow should decrease to minimum according to Step 4 of the"Test Specifications". If the discharge flow does not decrease according to Step 4 of the"Test Specifications" the on/off solenoid may not be functioning properly.

   Decreased current to the on/off solenoid (53) to zero.

5. Increase input speed according to Step 5 of the"Test Specifications". Increase the discharge flow by turning adjustment for discharge flow (57) according to Step 5 of the"Test Specifications". Adjust the input RPM to the value in Step 5. Increase the pump discharge pressure to the value in Step 5 of the"Test Specifications". Compare the actual values from the case drain with the values in Step 5 of the"Test Specifications". This value is an indication of the pump efficiency. If the case drain is more than the value given in Step 5 of the"Test Specifications" the pump may not be mechanically feasible. The pump is to be internally inspected.

6. Adjust the input RPM to the value in Step 6 of the"Test Specifications". Increase the pump discharge pressure to the value in Step 6 of the"Test Specifications". Turn the adjustment screw for the high pressure cut (52) until the actual high-pressure cut value is equal to the value in Step 6. The discharge flow should decrease to the value in Step 6 in the"Test Specifications" when the high-pressure cut is reached.

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Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.

Reduce RPM and all pressures to zero. Remove the component from the test bench. Drain the oil from the pump. Plug all of the ports.

Test Specifications

Tooling