Bench Test Procedure for Hydraulic Piston Pumps {0738, 5070} Caterpillar

Wheel Loader

966K Series XE (S/N: NGX1-UP)

966M Series XE (S/N: P6C1-UP; B8P1-UP)

972M Series XE (S/N: M5S1-UP; EDW1-UP)

Introduction

© 2016 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 Service Tool Division. 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, please 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) in order 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

Port Locations

Illustration 7	g03275159
Port locations and adjustments (49) Electrical connector for solenoid (50) Solenoid (51) Gauge port for discharge pressure (52a, 52b, 52c, 52d) Case drain (53) Discharge port (54) Suction port (55) Locknut for adjustment screw for minimum displacement (56) Adjustment screw for minimum displacement (57) Locknut for adjustment screw for maximum displacement (58) Adjustment screw for maximum displacement (59) Gauge port for destroke pressure

Illustration 8	g03275310
Pump schematic (50) Solenoid (51) Gauge port for discharge pressure (52) Case drain (53) Discharge port (54) Suction port (59) Gauge port for destroke pressure

Pump Setup

Note: A power supply is required to operate the solenoid. The power supply should be capable of delivering 0 mA to 2.0 A with an infinite setting in that range.

1. Mount the pump with Solenoid (50) on top.

2. Connect a one inch high pressure "XT-6ES" rated hose from Discharge port (53) to the flow meter inlet on the test bench.

3. Connect a one inch high pressure "XT-6ES" rated hose from the outlet of the flow meter on the test bench back to the tank.

4. Connect the oil supply suction hose to Suction port (54).

5. Fill the pump case with oil. Pour oil directly into case drain port (52a) or (52c) until the case is full.

6. Connect a hose from the case drain port (52a) or (52c) to an in-line flow meter. Direct the oil from the flow meter back to the reservoir.

7. Connect a 8T-0857 Pressure Gauge (0-1450 PSI) to Gauge port for discharge pressure (51).

8. Open the oil supply valve in order to fill the pump. Purge all air from the suction line before rotating the pump. Loosen the suction hose at the pump until oil leaks from the connection. Tighten the suction hose.

9. Connect a power supply to Electrical connector for the solenoid (49) in order to operate the solenoid valve. The power supply should be capable of delivering 0 mA to 2.0 A with an infinite setting in that range.

10. 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 the rotation of the test bench for proper direction.

Test Procedure

Note: The steps in the procedure correlate with the steps in the test specifications according to your specific part number.

The hydraulic oil in the test bench should meet an ISO rating of 16/13. 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)

Note: The swashplate sensor calibration procedure and high-pressure cut setting procedure cannot be performed due to lack of ECM control.

1. Set the current from the power supply according to the value in Step 1 of the Test Specifications. Start rotating the pump according to the RPM in Step 1 of the Test Specifications. Listen for abnormal noise. Verify that all the connections are not leaking. Check for leaks around shaft seals and control valves.

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

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   Illustration 9	g03293204
   Rough adjustment for maximum displacement. (57) Locknut for adjustment screw for maximum displacement (58) Adjustment screw for maximum displacement

2. This step will set the maximum displacement of the pump. For a rough starting point for the maximum displacement, see Illustration 9. Slowly set the pump RPM, current from the power supply, and the discharge pressure according to Step 2 of the Test Specifications. If the discharge flow of the pump does not match Step 2 of the Test Specifications, adjustment of the maximum displacement will be required. To increase flow, loosen Locknut (57) and turn Adjustment screw for maximum displacement (58) counter-clockwise. To decrease flow, loosen Locknut (57) and turn Adjustment screw for maximum displacement (58) clockwise. Adjust to the value in Step 2 of the Test Specifications. Torque locknut (57) to 190 ± 15 N·m (140 ± 11 lb ft) after adjustment.

   Note: Leave load control setting on test bench used in Step 2 of the Test Procedure for Step 3 of the Test Procedure. Once the knob is set for Step 2 of the Test Procedure, do not turn until Step 3 of the Test Procedure is complete.

   Note: Do not remove the Adjustment screw for minimum displacement (56) from the pump housing at any time. Be aware of this during the next step.

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   Illustration 10	g03306516
   Rough adjustment for minimum displacement. (55) Locknut for adjustment screw for minimum displacement (56) Adjustment screw for minimum displacement

3. This step will set the minimum displacement of the pump and check the low standby pressure of the pump. For a rough starting point for setting the minimum displacement, see Illustration 10.

   Disconnect 8T-0857 Pressure Gauge (0-1450 PSI) from Gauge port for discharge pressure (51) and connect 8T-0855 Pressure Gauge (0-580 PSI) to Gauge port for discharge pressure (51).

   1. Set the pump RPM and current from the power supply according to Step 3.a of the Test Specifications. Do not adjust discharge load valve as stated in the Note above. The pump discharge pressure should read the value in Step 3.a of the Test Specifications. If the pump discharge does not fall within the specified range, adjustment of the Adjustment screw for minimum displacement (56) is necessary. If the discharge pressure is too high, loosen Locknut (55) and slowly turn Adjustment screw for minimum displacement (56) counter-clockwise until the discharge pressure is correct. If the discharge pressure is too low, loosen Locknut (55) and slowly turn Adjustment screw for minimum displacement (56) clockwise until the discharge pressure is correct.

   2. Turn Adjustment screw for minimum displacement (56) counter-clockwise 45 degrees (1/8 turn) plus or minus 15 degrees. Torque Locknut (55) to 190 ± 15 N·m (140 ± 11 lb ft) after adjustment.

      Note: Steps 3.c and 3.d will verify the minimum displacement setting and the low standby pressure setting performed in Steps 3.a and 3.b of the Test Procedure.

   3. Set the pump RPM and the current from the power supply according to Step 3.c of the Test Specifications. Be sure the minimum and maximum discharge pressures are within the range specified in Step 3.c of the Test Specifications.

   4. Set the pump RPM and the current from the power supply according to Step 3.d of the Test Specifications. Be sure the minimum and maximum discharge pressures are within the range specified in Step 3.d of the Test Specifications.
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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.

   Show/hide table

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

4. This step will check the pump control function.

   Disconnect 8T-0855 Pressure Gauge (0-580 PSI) from Gauge port for discharge pressure (51).

   Set the pump RPM, current from the power supply, and the discharge pressure according to Step 4 of the Test Specifications. The discharge flow should be the value in Step 4 of the Test Specifications as the current is adjusted from maximum current to minimum current and back to maximum current in Step 4 of the Test Specifications.

   Note: The high-pressure cut cannot be tested due to lack of ECM control.

   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