Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Wheel Loader

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

966M Series XE (S/N: FL21-UP)

972M Series XE (S/N: L9S1-UP)

Introduction

© 2017 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 may be violation of intellectual property law.

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 feedback for in the Service Information System website. 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 (on-line)

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

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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"Test Specifications"and the "Tooling" sections. Both sections are displayed toward the back 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 1	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 2	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 3	g01063314
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 4	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 5	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 6	g03099941
Port locations (49) Adjustment screw for the high-pressure cut (50) Suction port (51) Discharge port for piston pump (52) Outlet port for gerotor pump (53) Inlet port for piston pump (54) Case drain

Illustration 7	g03100057
Schematic (49) Adjustment screw for the high-pressure cut (50) Suction port (51) Discharge port for piston pump (52) Outlet port for gerotor pump (53) Inlet port for piston pump (54) Case drain

Pump Setup

Illustration 8	g03112658
Pump Setup Schematic (49) Adjustment screw for the high-pressure cut (50) Suction port (51) Discharge port for piston pump (52) Outlet port for gerotor pump (53) Inlet port for piston pump (54) Case drain

Illustration 9	g03119441
Pressure Relief Valve Assembly (55) 8T-0862 Pressure Gauge (56) 6V-4144 Quick Connect Coupler (57) 6V-3965 Fitting (58) 3J-1907 O-Ring Seal (59) 5P-2574 Connector (60) 3K-0360 O-Ring Seal (61) 231-1286 Pressure Relief Valve (62) Adjustment screw for the pressure relief valve (63) 120-9181 Valve Body (64) 105-7704 Tee (65) 5P-4588 Adapter (66) 3R-5387 Connector (67) 8C-3999 Pipe Adapter (68) 8C-7334 Adapter (69) 228-7093 O-Ring Seal (70) 329-5515 Tee As (Comes with O-Ring Seals (69) and (71)) (71) 238-5084 O-Ring Seal

1. Assemble Pressure Relief Valve Assembly (see Illustration 9). Connect the Pressure Relief Valve Assembly to Outlet port for gerotor pump (52) (See Illustrations 8 and 9). Connect a 1 inch high pressure "XT-6" rated hose from 329-5515 Tee As to Inlet port for piston pump (53) (See Illustration 8).

2. Mount pump with pump control on bottom and Case drain (54) near top.

3. Connect a 1 inch hose to the 5P-2974 Connector (59) to direct the residual oil to the sump (See Illustrations 8 and 9).

   Note: There will be a substantial amount of residual oil exiting 5P-2974 Connector (59), especially when the high-pressure cut is reached during Step 4 of the Test Procedure. Direct oil accordingly with hose secured.

   Note: Because the pressure cutoff is relatively low for this pump control, an 8T-0855 Pressure Gauge (0-500 psi) is necessary to accurately measure the discharge pressure. The test loop circuit pressure gauge is not accurate enough for setting the high-pressure cut in this case. See next step.

4. Connect a 1 inch high pressure "XT-6" rated hose from Discharge port for piston pump (51) to the flow meter inlet on the test bench. Place a Tee between Discharge port for piston pump (51) and the flow meter inlet on the test bench. Connect an 8T-0855 Pressure Gauge (0-500 psi) to the Tee.

5. Connect the oil supply suction hose to Suction port (50).

6. 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 fitting.

7. Fill the pump case with oil before rotating. Pour oil directly into a Case drain (54) until the case is full.

8. Connect an in-line flow meter to the Case drain (54). Direct the oil from the in-line flow meter back to the tank.

9. 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	g01378800
Pump Characteristics (F) Discharge Flow (P) Discharge Pressure

1. Before rotating the pump, be sure that the Adjustment screw for the pressure relief valve (62) is completely opened (turned completely counter-clockwise). Start rotating the pump according to the RPM in Step 1 of the"Test Procedure". Adjust 231-1286 Pressure Relief Valve (61) to the charge pressure in Step 1 of the Test Specifications by turning the Adjustment screw for the pressure relief valve (62), if necessary. Listen for abnormal noise and verify flow from the pump. Be sure that all connections are secure and not leaking. Check for leaking shaft seals and control valve connections.

2. Slowly increase the input RPM to the value in Step 2 of the Test Specifications. Adjust 231-1286 Pressure Relief Valve (61) to the charge pressure in Step 2 of the Test Specifications, if necessary. The pump may not be feasible if the actual flow is less than the value in Step 2 of the Test Specifications. The pump should be disassembled and inspected.

3. Increase the pump discharge pressure to the value in Step 3 of the Test Specifications. Adjust 231-1286 Pressure Relief Valve (61) to the charge pressure in Step 3 of the Test Specifications, if necessary. Compare the actual case drain value with the case drain value in Step 3 of the Test Specifications. This value is an indication of the pump efficiency. The pump may not be feasible if the case drain is more than the value in Step 3 of the Test Specifications. The pump should be disassembled and inspected.

   Note: There will be a substantial amount of residual oil exiting 5P-2974 Connector (59), especially when the high-pressure cut is reached during Step 4 of the Test Procedure. Direct oil accordingly with hose secured.

4. Increase the pump discharge pressure to the value in Step 4 of the Test Specifications. Adjust 231-1286 Pressure Relief Valve (61) to the charge pressure in Step 4 of the Test Specifications, if necessary. Turn the adjustment screw for the high pressure cut (49) until the actual high-pressure cut value is equal to the value in Step 4 of the Test Specifications. Pump discharge flow should be zero 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. Cap and plug all ports.

Test Specifications

Tooling