Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Mining Truck

794 AC (S/N: HRT1-UP)

Off-Highway Truck/Tractor

793D (S/N: FDB1-UP)

794 AC (S/N: MN51-UP; MT51-UP)

795F AC (S/N: ERM1-UP)

795FAC XQ (S/N: SNT1-UP)

796 (S/N: HRY1-UP; HRZ1-UP)

798 (S/N: ST71-UP)

798 AC (T2) (S/N: ST31-UP)

Introduction

© 2014 Caterpillar All Rights Reserved. This guideline is for the use of Caterpillar Dealers only. Unauthorized use of this document or the proprietary processes therein without permission bay be violation of intellectual property law. Information contained within 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. In order to address an urgent need, use the following to relay your request to Caterpillar Repair Process Engineering:

• Cat Dealer Technical Communicator

• Dealer Solution Network

• Cat 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. The test procedure should be used with the specific test specifications and tooling given 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) in order to view the latest version.

References

Connections for the Caterpillar Hydraulic Test Center

Illustration 2	g01302576
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	g01302577
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	g01302579
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 5	g01302580
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	g01302581
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

Port Locations

Illustration 7	g03617977
For use with part numbers 198-6040, 299-3935, and 344-3943. (49) Case drain port (50) Pressure cutout set screw (51) Discharge port (52) Maximum swashplate angle set screw (53) Suction port (54) Destroke pressure port (not used in test) (55) Discharge port (gage) (56) Control pressure port (not used in test) (57) Minimum swashplate angle set screw

Illustration 8	g01304184
For use with part number 301-9250. (49) Case drain port (50) Pressure cutout set screw (51) Discharge port (52) Maximum swashplate angle set screw (53) Suction port (54) Destroke pressure port (not used in test) (55) Discharge port (gage) (56) Control pressure port (not used in test) (57) Minimum swashplate angle set screw

Illustration 9	g01302585
(49) Case drain port (50) Pressure cutout set screw (51) Discharge port (52) Maximum swashplate angle set screw (53) Suction port (54) Destroke pressure port (not used in test) (55) Discharge port (gage) (56) Control pressure port (not used in test) (57) Minimum swashplate angle set screw

Pump Pre-Test Set Up

1. Connect oil supply line to suction port (53). Connect a flow meter to one of the case drain ports (49). Connect an XT5-ES line from the discharge port (51) to the test bench inlet port (32). Connect a line from the test bench flow meter outlet port (30) to tank.

2. Purge all air from the suction line. Loosen the suction hose at the pump until oil leaks from the connection. Tighten the suction fitting.

3. Fill the pump case with oil. Pour oil directly into a case drain port (49) until the case is full.

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

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 10	g01302586
Pump P*Q Curve

1. Start rotating the pump according to the RPM in Step 1 of the test specifications. Listen for abnormal noise and verify that there is flow from the product. Check to see that all connections are secure and not leaking. Check for case leaks such as, shaft seals and control valve connections.

2. Slowly increase the pump input RPM to the value given in Step 2 of the test specifications. If the pump is equipped with a maximum swashplate angle set screw, the pump may need adjusted to achieve the correct flow rate. If the actual flow is less than the value given in Step 2 of the test specifications, the pump may not be mechanically sound. The pump should be disassembled and inspected.

3. Increase the pump discharge pressure to the value given in Step 3 of the test specifications. Compare the actual case drain value to the value given in Step 3 of the test specifications. This value is an indication of the pumps efficiency. If the case drain is more than the value given in Step 3 of the test specifications, the pump may not be mechanically sound. The pump should be disassembled and inspected.

4. Increase the pump discharge pressure to the value given in Step 4 of the test specifications. Adjust the pressure cut out set screw (50) until the actual cut-off value is equal to the value given in Step 4 of the test specifications. Pump discharge flow should be near zero when the cut-off pressure 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 component from the test bench. Drain the oil from the pump. Cap and plug all ports.

Test Specifications

Tooling