Bench Test Procedure for Hydraulic Piston Pumps{0738, 3203, 5070} Caterpillar

Track-Type Tractor:

D10T (S/N: RAB1-UP; JJW1-UP)

Introduction

© 2013 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 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 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 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 (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, type of controller, and internal components of the pump. Refer to the Test Specifications and the Test Bench 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	g01088926
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	g01088929
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	g01088930
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 5	g01088934
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 (33) "Flow meter 1" inlet (34) Auxiliary pump oil supply (35) "Flow meter 1" inlet

Illustration 6	g01088935
Control and Gauges for the Test Bench (36) Auxiliary pump pressure (37) Signal pressure (38) Control for signal pressure (39) "Flow meter 1" discharge pressure (40) Control for auxiliary pump pressure (41) "Flow meter 2" discharge pressure (42) Auxiliary pump flow 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	g03411665
Typical port locations. (49) Air purge port (50a) Gauge port for stroking pressure (50b) Gauge port for stroking pressure (51) Filter inlet port (52) Filter outlet port (53a) Cross-over relief valve (53b) Cross-over relief valve (54) Electrical connector for stroking solenoid (55a) Gauge port for discharge pressure (55b) Gauge port for discharge pressure (56) Gauge port for charge pressure (57) Charge pressure relief valve (58a) Case drain (58b) Case drain (59) Gauge port for stroking pressure supply (60) Adjustment screw for mechanical zero (61a) Discharge port (61b) Discharge port (62) Adjustment screw for high-pressure cut (63) Electrical connector for pressure reducing valve (64) Gage port for high pressure (65) Suction port

Illustration 8	g03411278
Hydraulic schematic (49) Air purge port (50a) Gauge port for stroking pressure (50b) Gauge port for stroking pressure (51) Filter inlet port (52) Filter outlet port (53a) Cross-over relief valve (53b) Cross-over relief valve (54) Electrical connector for stroking solenoid (55a) Gauge port for discharge pressure (55b) Gauge port for discharge pressure (56) Gauge port for charge pressure (57) Charge pressure relief valve (58a) Case drain (58b) Case drain (59) Gauge port for stroking pressure supply (60) Adjustment screw for mechanical zero (61a) Discharge port (61b) Discharge port (62) Adjustment screw for high-pressure cut (63) Electrical connector for pressure reducing valve (64) Gage port for high pressure (65) Suction port

9U-5902 Rectifier Block

Illustration 9	g03413600
9U-5902 Rectifier Block Connections (66) High pressure port "from pump discharge" (67) Outlet "to flow meter loop" (68) High pressure port" from pump discharge" (69) Low pressure return "from heat exchanger"

Illustration 10	g03413608
9U-5902 Rectifier Block Schematic (66) High pressure port "from pump discharge" (67) Outlet "to flow meter loop" (68) High pressure port "from pump discharge" (69) Low pressure return "from heat exchanger"

120-9181 Valve Body and 4C-4014 Relief Valve

Illustration 11	g03423268
120-9181 Valve Body Connections (70) Pressure relief outlet "to test bench reservoir" (71) Adjustment screw for pressure relief (72) Pressure relief inlet "from tee in pump charge filter loop"

Illustration 12	g03423292
120-9181 Valve Body Schematic (70) Pressure relief outlet (71) Adjustment screw for pressure relief (72) Pressure relief inlet

9U-5893 Heat Exchanger

Illustration 13	g03413613
9U-5893 Heat Exchanger Connections (73) Inlet "from flow meter loop" (74) Outlet "to rectifier block" (75) Water inlet (76) Water outlet

198-4240 Electric Pressure Gauge Group

Illustration 14	g03413617
198-4240 Electric Pressure Gauge Group (77) Pressure gauge (78) Red Transducer 34500 kPa (5000 psi) (79) Blue Transducer 3450 kPa (500 psi)

Note: Accuracy for mechanical zero position is crucial. The use of the 198-4240 Electric Pressure Gauge Group is Highly recommended.

Pump Setup

1. Mount the pump with suction port (65) facing down.

2. Connect a suction line from the oil supply on the test bench to suction port (65) .

3. Connect a 1 inch high pressure "XT6" hose from discharge port (61a) to the high pressure port (66) on the 9U-5902 Rectifier Block .

4. Connect a 1 inch high pressure "XT6" hose from discharge port (61b) to the high pressure port (68) on the 9U-5902 Rectifier Block .

5. Connect a 1 inch high pressure "XT6" hose from outlet port (67) on the rectifier block to the inlet port on the flow meter.

6. Connect a 1 inch high pressure "XT6" hose from the outlet port on the flow meter to the inlet port (73) on 9U-5893 Heat Exchanger .

7. Connect a 1 inch high pressure "XT6" hose outlet port (74) on the heat exchanger to inlet port (69) on the rectifier block. Connect water inlet port (75) and water outlet port (76) to a water supply.

8. Connect a 3/4 inch "XT3" hose from filter inlet port (51) to filter outlet port (52) with an in-line tee going to pressure relief inlet (72) on 120-9181 Valve Body . Use 4C-4014 Relief Valve cartridge with 120-9181 Valve Body . Direct the pressure relief outlet (70) on 120-9181 Valve Body back test bench reservoir.

9. Set adjustment screw for pressure relief (71) on 4C-4014 Relief Valve equal to the charge pressure value given in the Test Specifications.

10. Install pressure taps in both gauge ports for stroking pressure (50a) and (50b) .

11. Install pressure taps in both gauge ports for discharge pressure (55a) and (55b) .

12. Install a pressure tap in gauge port for charge pressure (56) .

13. Vent case drain port (58b) to test bench reservoir.

14. Fill the pump case with oil before rotating. Pour oil directly into a case drain port (58b) until the case is full.

15. Connect electrical power supply to electrical connector for stroking solenoid (54) .

16. Connect electrical power supply to electrical connector for pressure reducing valve (63) .

Adjustment for Mechanical Zero Position

Note: 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 pump for proper rotation.

Note: Before performing the adjustment for mechanical zero position the pump must be mechanically sound. Apply current to the electrical connector for pressure reducing valve (63) according to Step 1 of the Test Specifications. Start rotating the pump according to Step 1 of the Test Specifications. Verify that all connections are tight. Listen for abnormal noise. Check for leaks around shaft seals. Check for leaks around the control valves. Sustain oil flow to suction port (65) in Step 1 through 4 of the Adjustment for Mechanical Zero Position by adjusting the adjustment screw for pressure relief (71) on 4C-4014 Relief Valve .

1. Turn the load control on the test bench completely clockwise in order to control the pump discharge pressure. Start rotating the pump at the value in Step 1 of the Test Specifications. Vent the gauge ports for the stroking pressure (50a) and (50b) to the atmosphere. This will equalize the pressure on the servo spool. Install pressure gauges on gauge ports for discharge pressure (55a) and (55b). If the mechanical zero adjustment is incorrect, a discharge pressure higher than the charge pressure may occur.

2. Loosen the locknut and turn adjustment screw for the mechanical zero (60) clockwise. Continue to turn until pressure noticeably increases at either gauge port for discharge pressure (55a) or (55b). The increase in pressure will only be noticeable at one of the two gauge ports at a time. Mark the position of the adjustment screw for the mechanical zero (60).

   Repeat Step 2 of Adjustment for Mechanical Zero Position but turn the adjustment screw for mechanical zero (60) counterclockwise. The increase in pressure will be noticeable at the gauge port that did not increase in pressure previously.

3. A mark should be placed halfway between position one and position two. Turn the adjustment for the mechanical zero (60) to the midpoint of both marks. There should be less than a 34.5 kPa (5 psi) pressure differential between gauge ports for discharge pressure (55a) and (55b) .

4. Stop rotating the pump. Stop auxiliary oil flow to suction port (65). Turn the load control on the test bench for pump discharge pressure counterclockwise. Allow the discharge pressure of the pump to decrease. Disconnect pressure gauges from ports (55a) and (55b). Disconnect hoses from ports (50a), (50b), (55a), and (55b) .

Test Procedure

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

1. Apply current to the electrical connector for pressure reducing valve (63) to the value in Step 1 of the Test Specification. Start rotating the pump according to Step 1 of the Test Specifications. Listen for abnormal noise. Verify that all connections are tight. Check for leaks around shaft seals. Check for leaks around the control valve. Check the charge pressure at the gauge port for charge pressure (55). Compare the charge pressure with the value in Step 1 of the Test Specifications. If the charge pressure is not within the Test Specifications, adjust the adjustment screw for pressure relief (71) on 4C-4014 Relief Valve .

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

2. Increase the input RPM according to Step 2 of the Test Specifications. Slowly reduce current to electrical connector for pressure reducing valve (63) to the value in Step 2 of the Test Specifications to stroke the pump and acquire flow. Verify that the main discharge flow is within specifications. If the values are not within specification the pump may not be mechanically feasible.

   Slowly apply current to electrical connector for stroking solenoid according the value in Step 2 of the Test Specification and repeat Step 2 of the Test Procedure to test the other side of the pump.

3. Pump efficiency will be tested in this step. Increase pump discharge pressure to the value in Step 3 of the Test Specifications. Calculate the total loss in discharge flow. The pump may not be mechanically feasible if the total loss is higher than the allowable value in Step 3 of the Test Specifications.

   Calculate the total loss by subtracting the discharge flow that was recorded in Step 3 of the Test Procedure from the discharge flow recorded in Step 2 of the Test Procedure.

   Example: "Step 2 flow" 162 L/min (42.8 gpm) - "Step 3 flow" 158 L/min (41.7 gpm) = "total loss" 4 L/min (1.1 gpm). The "max. allowable loss" is 7.2 L/min (1.9 gpm).

   The pump in the example is acceptable because the total loss is less than the maximum allowable loss.

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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 during adjustment of the high pressure relief valve if recommended hose maintenance practices are not followed. Escaping fluid under pressure can penetrate body tissue causing serious injury, and possible death. Adjustment of the high pressure cut or pressure override valve shall only be performed when the pump is operating at a zero discharge pressure condition. Continuation of the pump test procedure can be resumed when this high pressure adjustment is completed.

4. The cross-over relief valves will be tested in this step. Turn the adjustment screw for high-pressure cut (62) completely clockwise. Increase pump discharge pressure to the value in Step 4 of the Test Specification. Discharge flow will drop to zero when the cross-over relief valve opens. If the cross-over relief valve does not open at the pressure in Step 4 of the Test Specifications, slowly back out the adjustment screw for cross-over relief valve (53a) or (53b) on the high pressure side of the pump until the cross-over relief valve opens.

   Reduce pump discharge pressure to zero. Reduce current to electrical connector for stroking solenoid (54) to zero. Repeat Step 4 of the Test Procedure to test the other side of the pump.

5. The high-pressure cut will be tested in this step. Adjust pump discharge pressure to the value in Step 5 of the Test Specification. Discharge flow will drop to zero when the high-pressure cut is reached. If high-pressure cut is not reached, slowly back out the adjustment screw for high-pressure cut (62) until 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 pressure to zero. Remove component from test bench. Drain oil from pump. Cap or plug all ports.

Test Specifications

Test Bench Tooling