Bench Test Procedure For Hydraulic Piston Pumps {5070} Caterpillar

Vibratory Asphalt Compactor

CCS7 (S/N: 4B21-UP)

Vibratory Soil Compactor

CP34 (S/N: 5151-UP)

CP44B (S/N: 4P41-UP; GNB1-UP)

CS34 (S/N: 5141-UP)

CS44B (S/N: CS31-UP; 4G31-UP; RGE1-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 technical questions when using this document, work with your Dealer Technical Communicator (TC).

To report suspected errors, inaccuracies, or suggestions regarding the document, submit a form for feedback in the Service Information System (SIS Web) interface.

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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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.

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

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	g01351819
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	g01351822
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	g01351830
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 5	g01351833
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	g01351834
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

This piston pump is produced with multiple type housings. Port locations will vary. Match the correct illustration with the pump that is being worked on.

Illustration 7	g03809256
Port locations and adjustments (49) Air bleed port for front pump (50) Electrical connector for neutral start switch (51) Mechanical displacement control for front pump (52) Gauge port for charge pressure (53) Gauge port for discharge pressure (54) Gauge port for discharge pressure (55) Gauge port for control pressure (56) Mechanical displacement control for front pump (57) Air bleed port for rear pump (58) Gauge port for stroking pressure (59) Adjustment screw for maximum pump displacement (60) Electrical connector for control cutoff solenoid (61) Adjustment for crossover relief valve (62) Gauge port for charge pressure (63) Adjustment for crossover relief valve (64) Adjustment for crossover relief valve (65) Adjustment for crossover relief valve (66) Case drain port (67) Adjustment screw for maximum pump displacement (68) Adjustment screw for charge relief valve (69) Gauge port for stroking pressure (70) Case drain port (71) Adjustment screw for maximum pump displacement (72) Gauge port for stroking pressure (73) Discharge port "C" (74) Charge inlet port (75) Gauge port for stroking pressure (76) Adjustment screw for maximum pump displacement (77) Case drain port (78) Discharge port "B" (79) Discharge port "A" (80) Gauge port for discharge pressure (81) Gauge port for discharge pressure (82) Discharge port "D"

Illustration 8	g03809259
Hydraulic schematic (49) Air bleed port for front pump (50) Electrical connector for neutral start switch (51) Mechanical displacement control for front pump (52) Gauge port for charge pressure (53) Gauge port for discharge pressure (54) Gauge port for discharge pressure (55) Gauge port for control pressure (56) Mechanical displacement control for front pump (57) Air bleed port for rear pump (58) Gauge port for stroking pressure (60) Electrical connector for control cutoff solenoid (61) Adjustment for crossover relief valve (62) Gauge port for charge pressure (63) Adjustment for crossover relief valve (64) Adjustment for crossover relief valve (65) Adjustment for crossover relief valve (66) Case drain port (68) Adjustment screw for charge relief valve (69) Gauge port for stroking pressure (70) Case drain port (72) Gauge port for stroking pressure (73) Discharge port "C" (74) Charge inlet port (75) Gauge port for stroking pressure (77) Case drain port (78) Discharge port "B" (79) Discharge port "A" (80) Gauge port for discharge pressure (81) Gauge port for discharge pressure (82) Discharge port "D"

9U-5902 Rectifier Block

Illustration 9	g03809557
9U-5902 Rectifier Block Connections

Illustration 10	g03809567
9U-5902 Rectifier Block Schematic (83) High-pressure port (84) High-pressure outlet (85) High-pressure port (86) Low-pressure inlet

9U-5893 Heat Exchanger

Illustration 11	g03809569
9U-5893 Heat Exchanger Connections (87) Inlet (88) Outlet (89) Water inlet (90) Water outlet

Set up for the Front Pump

Note: Only test one pump at a time on tandem pumps. Isolate one of the pumps by connecting a hose between the discharge ports on the pump that is not being tested.

1. A power supply is required to operate the solenoid on this pump. The power supply should be able to deliver 0 mA to 1600 mA with an infinite setting in that range.

2. Connect a power supply to the control cutoff solenoid (60) to activate the control cutoff valve.

3. Install 8T-0855 Pressure Gauges 4000 kPa (580 psi) on the gauge port for the charge pressure (52) or (62) and the gauge port for control pressure (55).

4. Install 8T-0860 Pressure Gauges 40000 kPa (5800 psi) on the gauge ports for discharge pressure (53) and (80).

5. Connect a hose from charge inlet port (74) to the test bench auxiliary oil supply. The auxiliary oil supply should be capable of producing 3000 kPa (435 psi) and 56 L/min (14.8 US gpm).

   Note: Be sure to use XT-6ES rated hydraulic hose.

6. Connect pump discharge ports (78) and (79) to the 9U-5902 Rectifier Block high-pressure ports (83) and (85).

7. Connect the 9U-5902 Rectifier Block outlet (84) to the flow meter inlet on the test bench.

8. Connect the flow meter outlet to the 9U-5398 Heat Exchanger inlet (87) .

9. Connect the 9U-5398 Heat Exchanger outlet (88) to the low-pressure return (86) on the 9U-5902 Rectifier Block.

10. Use the rear housing case drain port (70) on tandem pumps. Fill the pump case with oil. Pour oil directly into a case drain port until the case is full.

11. Connect an in-line flow meter to the case drain port (70). Vent the case to the atmosphere. Make sure that the case drain flow is directed into the sump.

12. 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.

Adjustment for Mechanical Zero Position for the Front Pump

Note: Before performing the adjustment for mechanical zero the pump must be mechanically sound. 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. For pumps not equipped with a charge pump, be sure to sustain auxiliary oil flow to charge inlet port (74) in Steps 2 through 5 of the mechanical zero adjustment.

1. Turn the load control on the test bench completely clockwise. Turning clockwise will allow pump discharge pressure to increase in the following steps. Start rotating the pump at the value in Step 2 of the test specifications. This unit is not equipped with a charge pump. Be sure to sustain auxiliary oil flow to charge inlet port (74) in Steps 2 through 5 of the mechanical zero adjustment. If the mechanical zero adjustment is incorrect, a discharge pressure higher than the charge pressure may occur. Increase signal current to control cutoff solenoid (60) until the solenoid is energized.

2. Check the gauge ports for stroking pressure (69) and (75). Ensure that the pressure differential is less than 150 kPa (22 psi). Remove locking plates for adjustment screws for maximum displacement (67) and (76).

3. Turn the adjustment screws for pump displacement (67) and (76) counterclockwise three turns.

4. Stroke the pump by turning mechanical displacement control (51) clockwise until the stroking pressure at gauge port (69) is 200 kPa (29 psi) greater than at gauge port (75). Pressure should be greater at gauge port for discharge pressure (53) for clockwise pump rotation. Pressure should be greater at system pressure gauge port (80) for counterclockwise pump rotation.

5. Slowly turn the adjustment for pump displacement (67) clockwise until the system pressure differential is less than 150 kPa (22 psi) between gauge ports (53) and (80). This procedure sets the servo piston and swashplate to mechanical zero on the (67) side of the pump. Install and tighten the adjustment screw locking plates.

6. Repeat Steps 2 through 5, but stroke the pump in the opposite direction by turning mechanical displacement control (51) counterclockwise.

7. Stop rotating the pump. 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 (53) and (80). Reduce current to all solenoids to zero.

Test Procedure for the Front Pump

The ISO contamination rating of the hydraulic oil in the test bench should be ISO 16/13 or cleaner. 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 following test procedure steps correlate with the numbered steps in the test specification section according to your specific part number.

Illustration 12	g03809585
Mechanical displacement versus pump flow

1. The following steps verify the operation of the charge relief valve. Start rotating the pump according to Step 1 of the test specifications for several minutes to bring the oil to operating temperature. This pump will require auxiliary charge flow according to the value in 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. Check the gauge port for the charge pressure (52) or (62). Compare the actual charge pressure with the value in Step 1 of the test specifications. If the charge pressure is not within the test specifications, adjust the charge relief valve. Adjust the charge relief valve by turning the adjustment screw for charge relief valve (68) clockwise or counterclockwise accordingly.

   Note: Be sure that the front pump is mechanically zeroed before continuing to Step 2 of the test procedure.

2. This step will verify the operation of the mechanical displacement control and the final point of pump stroke.

   Slowly increase the input RPM and current to the control cut-off solenoid (60) to the value listed in Step 2 of the Test Specifications. Verify that the control cutoff solenoid is energized by checking for a pressure increase on the gauge port for control pressure (55). Slowly turn mechanical displacement control (51) completely clockwise. Discharge flow should increase to the value in Step 2 of the test specifications. This position is the end of pump stroke control. The pump is to be internally inspected if the discharge flow does not match the value in Step 2 of the test specifications.

3. This step will test pump efficiency.

   With the mechanical displacement control maintained in the stroked position, slowly increase the pump discharge pressure to the value in Step 3 of the test specifications. Measure pump leakage at this point. Calculate the total loss. If the total loss is higher than the allowable value in Step 3 of the test specifications, The pump may not be mechanically feasible.

   Subtract the discharge flow in Step 3 from Step 2. The remainder is your total loss.

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

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

4. This step will verify proper setting of the crossover relief valves.

   With the mechanical displacement control maintained in the stoked position, increase discharge pressure to the value in Step 4 of the Test Specifications. At this point, the discharge pressure should stop increasing and flow should drop to zero. If flow does not drop to zero at this pressure, the adjustment for crossover relief valve (65) should be adjusted accordingly.

Repeat Step 2 through Step 4 for the opposite side of the pump. Turn the mechanical displacement control counterclockwise to stroke the opposite side of the pump. The crossover relief adjustment for the opposite side of the pump is adjustment for crossover relief valve (64).

Show/hide table

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 the component from the test bench. Drain the oil from the pump. Plug all of the ports.

Set up for the Rear Pump

Note: Only test one pump at a time on tandem pumps. Isolate one of the pumps by connecting a hose between the discharge ports on the pump that is not being tested.

1. A power supply is required to operate the solenoid. The power supply should be able to deliver 0 mA to 1600 mA with an infinite setting in that range.

2. Connect a power supply to the solenoid (60) in order to activate the control cutoff valve.

3. Install 8T-0855 Pressure Gauges 4000 kPa (580 psi) on the gauge port for the charge pressure (52) or (62) and the gauge port for control pressure (55).

4. Install 8T-0860 Pressure Gauges 40000 kPa (5800 psi) on the gauge ports for discharge pressure (59b) and (59c).

5. Connect a hose from charge inlet port (74) to the test bench auxiliary oil supply. The auxiliary oil supply should be capable of producing up to 3000 kPa (435 psi) and 56 L/min (14.8 US gpm).

   Note: Be sure to use XT-6ES rated hydraulic hose.

6. Connect pump discharge ports (73) and (82) to the 9U-5902 Rectifier Block high-pressure ports (83) and (85).

7. Connect the 9U-5902 Rectifier Block outlet (84) to the flow meter inlet on the test bench.

8. Connect the flow meter outlet to the 9U-5398 Heat Exchanger inlet (87).

9. Connect the 9U-5398 Heat Exchanger outlet (88) to the low-pressure return (86) on the 9U-5902 Rectifier Block.

10. Use the rear housing case drain port on tandem pumps. Fill the pump case with oil. Pour oil directly into a case drain port (70) until the case is full.

11. Connect an in-line flow meter to the case drain port (70). Vent the case to the atmosphere. Make sure that the case drain flow is directed into the sump.

12. 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.

Adjustment for Mechanical Zero Position for the Rear Pump

Note: Before performing the adjustment for mechanical zero the pump must be mechanically sound. 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. For pumps not equipped with a charge pump, be sure to sustain auxiliary oil flow to charge inlet port (74) in Steps 2 through 5 of the mechanical zero adjustment.

1. Turn the load control on the test bench completely clockwise. Turning clockwise will allow pump discharge pressure to increase in the following steps. Start rotating the pump at the value in Step 2 of the test specifications. This unit is not equipped with a charge pump. Be sure to sustain auxiliary oil flow to charge inlet port (74) in Steps 2 through 5 of the mechanical zero adjustment. If the mechanical zero adjustment is incorrect, a discharge pressure higher than the charge pressure may occur. Increase signal current to control cutoff solenoid (60) until the solenoid is energized.

2. Check the gauge ports for stroking pressure (58) and (72). Ensure that the pressure differential is less than 150 kPa (22 psi). Remove locking plates for adjustment screws for maximum pump displacement (59) and (71).

3. Turn the adjustment screws for pump displacement (59) and (71) counterclockwise three turns.

4. Stroke the pump by turning mechanical displacement control (56) clockwise until the stroking pressure at gauge port (72) is 200 kPa (29 psi) greater than at gauge port (58). Pressure should be greater at gauge port for discharge pressure (81) for clockwise pump rotation. Pressure should be greater at system pressure gauge port (54) for counterclockwise pump rotation.

5. Slowly turn the adjustment for pump displacement (71) clockwise until the system pressure differential is less than 150 kPa (22 psi) between gauge ports (54) and (81). This procedure sets the servo piston and swashplate to mechanical zero on the (71) side of the pump. Install and tighten the adjustment screw locking plates.

6. Repeat Steps 2 through 5, but stroke the pump in the opposite direction by turning mechanical displacement control (56) counterclockwise.

7. Stop rotating the pump. 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 (54) and (81). Reduce current to all solenoids to zero.

Test Procedure for the Rear Pump

The ISO contamination rating of the hydraulic oil in the test bench should be ISO 16/13 or cleaner. 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 following test procedure steps correlate with the numbered steps in the test specification section according to your specific part number.

Illustration 13	g03809585
Mechanical displacement versus pump flow

1. The following steps verify the operation of the charge relief valve. Start rotating the pump according to Step 1 of the test specifications for several minutes in order to bring the oil to operating temperature. This pump will require auxiliary charge flow according to the value in 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. Check the gauge port for the charge pressure (52) or (62). Compare the actual charge pressure with the value in Step 1 of the test specifications. If the charge pressure is not within the test specifications, adjust the charge relief valve. Adjust the charge relief valve by turning the adjustment screw for charge relief valve (68) clockwise or counterclockwise accordingly.

   Note: Be sure that the rear pump is mechanically zeroed before continuing to Step 2 of the test procedure.

2. This step will verify the operation of the mechanical displacement control and the final point of pump stroke.

   Slowly increase the input RPM and current to the control cut-off solenoid (60) to the value listed in Step 2 of the Test Specifications. Verify that the control cutoff solenoid is energized by checking for a pressure increase on the gauge port for control pressure (55). Slowly turn mechanical displacement control (56) completely clockwise. Discharge flow should increase to the value in Step 2 of the test specifications. This position is the end of pump stroke control. The pump is to be internally inspected if the discharge flow does not match the value in Step 2 of the test specifications.

3. This step will test pump efficiency.

   With the mechanical displacement control maintained in the stroked position, slowly increase the pump discharge pressure to the value in Step 3 of the test specifications. Measure pump leakage at this point. Calculate the total loss. If the total loss is higher than the allowable value in Step 3 of the test specifications, The pump may not be mechanically feasible.

   Subtract the discharge flow in Step 3 from Step 2. The remainder is your total loss.

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

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

4. This step will verify proper setting of the crossover relief valves.

   With the mechanical displacement control maintained in the stoked position, increase discharge pressure to the value in Step 4 of the Test Specifications. At this point, the discharge pressure should stop increasing and flow should drop to zero. If flow does not drop to zero at this pressure, the adjustment for crossover relief valve (63) should be adjusted accordingly.

Repeat Step 2 through Step 4 for the opposite side of the pump. Turn the mechanical displacement control counterclockwise to stroke the opposite side of the pump. The crossover relief adjustment for the opposite side of the pump is adjustment for crossover relief valve (71).

Show/hide table

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 the component from the test bench. Drain the oil from the pump. Plug all of the ports.

Test Specifications

Test Bench Tooling