Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Asphalt Compactor

CB-534D (S/N: EAA1-UP; FEA1-UP; C2B1-UP; C4B1-UP; FGH1-UP)

CB-564D (S/N: C6D1-UP; D4M1-UP)

CB64 (S/N: CB51-UP; DJM1-UP)

Paving Compactor

CD54 (S/N: J5R1-UP)

Vibratory Asphalt Compactor

CB54 (S/N: K3J1-UP)

Vibratory Soil Compactor

CP74B (S/N: 4911-UP; 5121-UP; P741-UP; 7441-UP; CP71-UP; M7B1-UP)

CP76 (S/N: JCP1-UP)

CP76B (S/N: J761-UP)

CS74B (S/N: 4901-UP; 4411-UP; C741-UP; CS41-UP; E7E1-UP; B7M1-UP)

CS76 XT (S/N: JCS1-UP)

CS76B (S/N: 4921-UP; CB71-UP; L9H1-UP)

CS78B (S/N: 4431-UP; 4931-UP; 5131-UP; M781-UP; S781-UP; M8M1-UP)

CS79B (S/N: C791-UP)

Introduction

© 2018 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. 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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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) to view the latest version.

References

Connections for the Caterpillar Hydraulic Test Center

Illustration 2	g01084214
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	g01084216
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	g01084217
Connections for the Test Bench (26) "Flow meter 1" loop and "Flow meter 2" loop (27) Oil Supply

Illustration 5	g01084219
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	g01084221
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	g01217897
Hydraulic schematic, typical port locations, and adjustments (49) Gauge port for stroking pressure (50) Adjustment screw for maximum displacement (51) Solenoid B (52) Gauge port for discharge pressure (53) Gauge port for discharge pressure (54) Solenoid A (55) Adjustment screw for mechanical centering (56) Adjustment screw for maximum displacement (57) Gauge port for stroking pressure (58) Gauge port for control pressure (59) Case drain port (60) Port for auxiliary oil supply (61) Electrical connector for solenoid (62) Discharge port (63) Discharge port (64) Adjustment screw for high-pressure cut (65) Case drain port

9U-5902 Rectifier Block

Illustration 8	g01172755
9U-5902 Rectifier Block Connections

Illustration 9	g01172756
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"

9U-5893 Heat Exchanger

Illustration 10	g01172839
9U-5893 Heat Exchanger Connections (70) Inlet "from flow meter loop" (71) Outlet "to rectifier block" (72) Water inlet (73) Water outlet

Pump Setup

Note: A power supply is required to operate the solenoid. The power supply should be capable of delivering 0 mA to 1.5 A with an infinite setting in that range.

1. Mount the pump with a case drain port (59) or (65) upward.

2. Connect pump discharge ports (62) and (63) to the 9U-5902 Rectifier Block high-pressure ports (66) and (68).

3. Connect the 9U-5902 Rectifier Block outlet (67) to the flow meter inlet on the test bench.

4. Connect the flow meter outlet to the 9U-5398 Heat Exchanger inlet (70) .

5. Connect the 9U-5398 Heat Exchanger outlet (71) to the low-pressure return (69) on the 9U-5902 Rectifier Block. Connect the water inlet port (72) and the water outlet port (73) to a water supply.

6. Connect the auxiliary oil outlet from the test bench to the auxiliary oil supply port (60). The auxiliary oil supply should be capable of producing 3000 kPa (435 psi) and 24.5 L/min (6.5 US gpm).

7. Fill the pump case with oil. Pour oil directly into a case drain port (59) or (65) until the case is completely full. Connect a line from case drain port (59) or (65) to test bench reservoir.

8. Connect power supply to electrical connector for solenoid (61).

9. 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.

Mechanical Zero Position for the Pump

1. Vent ports for stroking pressure (49) and (57) to atmosphere. This will equalize the pressure on the servo spool. Install 8T-0857 Pressure Gauges on ports (52) and (53). Supply auxiliary flow to port (60) according to the value in the test specifications. Start rotating the pump to 600 RPM. Turn the load control on the test bench completely "clockwise" for the pump discharge pressure. If the mechanical zero adjustment is incorrect, a discharge pressure higher than charge pressure may occur.

2. Turn the adjustment screw for mechanical centering (55) clockwise. Continue to turn until a pressure of 1380 kPa (200 psi) above charge pressure is achieved. This pressure will be seen on a gauge port for discharge pressure (52) or (53). Mark the position of the adjustment screw for mechanical centering (55).

3. Turn adjustment screw for mechanical centering (55) counterclockwise. Continue to turn until a pressure of 1380 kPa (200 psi) above charge pressure is achieved on the other gauge port for discharge pressure (52) or (53). Mark the position of the adjustment screw for mechanical centering (55).

4. A mark should be placed halfway between position one and position two. Turn the adjustment screw for mechanical centering (55) to the midpoint of both marks. There should be less than a 34.5 kPa (5 psi) pressure differential between pump gauge ports (52) and (53).

5. Turn the load control on the test bench for pump discharge pressure counterclockwise. Stop rotating the pump and allow pump pressure to dissipate. Disconnect pressure gauges from ports (52) and (53). Plug gauge ports for stroking pressure (52) and (53).

Test Procedure

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

The ISO contamination rating of the hydraulic oil in the test bench should be at least 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)

1. Supply auxiliary flow to port for auxiliary oil supply (60) according to the value in Step 1 of the test specifications. Start rotating the pump according to Step 1 of the test specifications. Listen for abnormal noise. Verify flow from the pump. Verify that all connections are tight. Check for leaks around shaft seals. Check for leaks around the control valve. Check the charge relief valve by the amount of discharge pressure shown at the test bench. Compare the charge relief valve pressure with the value in Step 1 of the test specifications. If the charge pressure is not within test specifications, then the charge relief valve may not be mechanically feasible.

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

   Note: The pump has two separate solenoids. Test one solenoid at a time then repeat Steps 2 through 5 to test the other solenoid. Under a common test condition, the discharge flows will not have the same values for solenoid A (54) and solenoid B (51) . There are two separate rows of discharge flow values in table 6 of the test specifications.

2. Slowly increase the input RPM to the value in Step 2 of the test specifications. Apply current to the solenoid being tested according to Step 2 of the test specifications. This is the point of upstroke of the pump.

3. Slowly increase the input RPM to the value in Step 3 of the test specifications. Record the actual discharge flow. Compare the actual discharge flow with the value in Step 3 of the test specifications.

   If the actual discharge flow is not within specifications, adjust the adjustment screw for the maximum displacement.

4. Slowly increase the pump discharge pressure to the value in Step 4 of the test specifications. Record the actual discharge flow. Measure the pump efficiency at this point. Calculate the total loss. If the total loss is higher than the allowable value in Step 4 of the test specifications, The pump may not be mechanically feasible.

   Subtract the actual discharge flow in Step 4 from Step 3. This is your total loss.

   Example "Step 4 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.

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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.

5. Slowly increase the pump discharge pressure to the value in Step 5 of the test specifications. The pump should be fully destroked when the discharge pressure in Step 5 is reached. The discharge flow should be zero when the high-pressure cut is reached. If the high-pressure cut is not within the test specifications, adjust accordingly. Turn the adjustment screw for the high pressure cut (64) clockwise to increase the pressure. To decrease the pressure, turn the adjustment screw (64) counterclockwise.

   Repeat Steps 2 through 5 for the other solenoid.

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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. Plug all of the ports.

Test Specifications

Test Bench Tooling

Caterpillar does not provide a specific power supply for operating solenoids on pumps. The power supply should be capable of providing 12 volts or 24 volts with the capability of delivering 0 mA to 1.5 A with an infinite setting through that range.