Bench Test Procedure for Hydraulic Piston Pumps {5070} Caterpillar

Cold Planer

PM310 (S/N: RH81-UP; NM91-UP; KWA1-UP; NMA1-UP)

PM312 (S/N: LJ91-UP; NA91-UP; NJ91-UP; NJX1-UP)

PM313 (S/N: J631-UP; DK91-UP; JH91-UP; JHZ1-UP)

Compact Wheel Loader

906K (S/N: L661-UP)

906M (S/N: H661-UP; K561-UP; Z661-UP)

907K (S/N: L771-UP)

907M (S/N: H771-UP; K571-UP; Z771-UP)

908K (S/N: L881-UP)

908M (S/N: H881-UP; K581-UP; Z881-UP)

910K (S/N: L221-UP)

910M (S/N: H221-UP)

914K (S/N: BF41-UP; L241-UP)

914M (S/N: H241-UP)

918M (S/N: H261-UP)

920K (S/N: B981-UP)

Hydraulic Shovel

6020B (S/N: D4Y1-UP; DNY1-UP)

Motor Grader

120 (S/N: E921-UP; E931-UP; E941-UP; E951-UP; Y9A1-UP; Y9B1-UP; Y9C1-UP; Y9D1-UP)

120L (S/N: E961-UP)

Introduction

© 2019 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. 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. To address an urgent need, 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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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 Illustration

Illustration 7	g03795779
Port locations (49) Charge filtration port (from filter) (50) Gauge port for control pressure (51) Electrical connector for control cutoff solenoid (52) Electrical connector for displacement control solenoid (53) Case drain port (54) Adjustment for pump displacement (55) Gauge port for stroking pressure (56) Discharge port (57) Suction port for charge pump (58) Discharge port (59) Gauge port for discharge pressure (60) Charge filtration port (to filter) (61) Adjustment for pump displacement (62) Electrical connector for displacement control solenoid (63) Gauge port for stroking pressure (64) Gauge port for charge pressure (65) Adjustment screw for crossover relief (66) Adjustment screw for charge relief (67) Adjustment screw for crossover relief (68) Gauge port for discharge pressure (69) Case drain port

Illustration 8	g03795782
Hydraulic schematic (49) Charge filtration port (from filter) (50) Gauge port for control pressure (51) Electrical connector for control cutoff solenoid (52) Electrical connector for displacement control solenoid (53) Case drain port (54) Adjustment for pump displacement (55) Gauge port for stroking pressure (56) Discharge port (57) Suction port for charge pump (58) Discharge port (59) Gauge port for discharge pressure (60) Charge filtration port (to filter) (61) Adjustment for pump displacement (62) Electrical connector for displacement control solenoid (63) Gauge port for stroking pressure (64) Gauge port for charge pressure (65) Adjustment screw for crossover relief (66) Adjustment screw for charge relief (67) Adjustment screw for crossover relief (68) Gauge port for discharge pressure (69) Case drain port

9U-5902 Rectifier Block

Illustration 9	g03805665
9U-5902 Rectifier Block Connections (70) High-pressure port (71) High-pressure outlet (72) High-pressure port (73) Low-pressure inlet

Illustration 10	g03805667
9U-5902 Rectifier Block Schematic (70) High-pressure port (71) High-pressure outlet (72) High-pressure port (73) Low-pressure inlet

9U-5893 Heat Exchanger

Illustration 11	g03805669
9U-5893 Heat Exchanger Connections (74) Inlet (75) Outlet (76) Water inlet (77) Water outlet

Pump Setup

1. At least two power supplies are required to operate the solenoids on this pump. The power supplies must be able to deliver 0 mA to 1600 mA with an infinite setting in that range.

2. Connect a power supply to electrical connector for displacement control solenoid (52) or (62) to operate the displacement control.

3. Connect a power supply to electrical connector for control cutoff solenoid (51).

4. Install 8T-0855 Pressure Gauge 4000 kPa (580 psi) on the gauge port for the charge pressure (64).

5. Install 8T-0860 Pressure Gauges 40000 kPa (5800 psi) on the gauge ports for discharge pressure (59) and (68).

6. Connect the charge filtration port (49) to the auxiliary oil supply. Suction port for charge pump (57) and charge filtration port (60) will not be used since this pump does not have a charge pump. Ports (57) and (60) should be plugged during testing.

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

7. Connect pump discharge ports (56) and (58) to the 9U-5902 Rectifier Block high-pressure ports (70) and (72).

8. Connect the 9U-5902 Rectifier Block outlet (71) to the flow meter inlet on the test bench.

9. Connect the flow meter outlet to the 9U-5398 Heat Exchanger inlet (74) .

10. Connect the 9U-5398 Heat Exchanger outlet (75) to the low-pressure return (73) on the 9U-5902 Rectifier Block.

11. Fill the pump case with oil. Pour oil directly into a case drain port (53) until the case is full.

12. Connect an in-line flow meter to the case drain port (53). Make sure that the case drain flow is directed into the sump.

13. 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

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.

1. Turn the load control on the test bench completelyclockwise. Turning clockwise will allow pump discharge pressure to increase in the following steps. Start rotating the pump at the value in Step 1 of the Test Specifications. Be sure to sustain oil flow to charge filtration port (49) in Steps 1 through 6 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 (51) until the control cutoff valve is activated.

2. Check the gauge ports for stroking pressure (55) and (63). Ensure that the pressure differential is less than 150 kPa (22 psi). Remove adjustment screws for the locking plate.

3. Turn the adjustment screws for pump displacement (54) and (61) counterclockwise three turns.

4. Stroke the pump by supplying current to (62) until the pressure at gauge port for stroking pressure (55) is 200 kPa (29 psi) greater than at gauge port for stroking pressure (63). Pressure should be greater at gauge port for discharge pressure (59) for clockwise rotation. Pressure should be greater at gauge port for discharge pressure (68) for counterclockwise rotation.

5. Slowly turn the adjustment for pump displacement (61) clockwise until the system pressure differential is less than 150 kPa (22 psi) between gauge ports (68) and (59). This procedure sets the servo piston and swashplate to mechanical zero on the discharge pressure port (61) side of the pump. Install and tighten the adjustment screw locking plates.

6. Repeat Steps 1 through 5 but stroke the pump in the opposite direction by supplying current to electrical connector for displacement control solenoid (52).

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 gauge ports for discharge pressure (59) and (68). Reduce current to all solenoids to zero.

Test Procedure

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

Note: The following test procedure steps correlate with the numbered steps in the Test Specification section according to your specific part number.

Illustration 12	g03792841
Electrical displacement control current versus pump discharge flow.

1. The following step verifies the operation of the charge relief valve. This pump will require sufficient auxiliary charge flow to maintain the charge pressure value in Step 1 of the Test Specifications. Start rotating the pump according to Step 1 of the Test Specifications for several minutes to bring the oil to operating temperature. 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 (64). 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 (66) clockwise or counterclockwise accordingly.

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

2. The following steps verify the operation of the electronic displacement control and the initial point of pump stroke.

   Slowly increase the input RPM and the current to the control cut-off solenoid (51) to the value 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 cutoff pressure (51). Slowly increase the current to the solenoid (52) or (62) to the value in Step 2 of the Test Specifications. This is the beginning of the pump stroke. Some flow meters may not be able to read discharge flows at the initial or low flow rates. Slowly increase the solenoid current until the flow meter can read the discharge flow. This is the initial point of pump stroke.

3. Slowly increase the current to displacement control solenoid (52) or (62) to the value in Step 3 in the Test Specifications. The pump should be at full stroke at this point. Record actual flow. The pump is to be internally inspected if the discharge flow does not match the value in Step 3 of the Test Specifications.

4. Slowly increase the pump discharge pressure to the value in Step 4 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 4 of the Test Specifications, The pump may not be mechanically feasible.

   Subtract the 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 5 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.

5. This step will verify setting of the pressure cutoff valves. Not all pumps are equipped with pressure cutoff valves. Refer to the Specifications table for your pump part number to determine if pressure cutoff specifications are provided. If not specifications are provided in Step 5, skip this step.

   Increase discharge pressure to the value given in Step 5 of the test specifications. Pump discharge flow should drop to zero when the pressure cutoff is reached. If the pressure cutoff is not correct, turn the adjustment screw for pressure cutoff until it is within specifications.

Note: Repeat Step 1 through Step 5 for the opposite side of the pump. Supply current to opposite solenoid (52) or (62).

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

Test Specifications

Tooling