RM-350B Road Reclaimer/Mixer Power Train Piston Pump Control (Rear Propel Pump) - Test and Adjust Caterpillar

Neutral Adjustment for Electronic Displacement Control

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the vibratory system.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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To prevent personal injury when checks are made while the machine is in operation, make sure only approved personnel are on the machine. Keep other personnel off the machine and in view of the operator. Make sure checks are done in an open area.

1. The following test must be repeated if there is any adjustments that need to be made to the swashplate mechanism. Refer to Test and Adjust Procedure, "Piston Pump Neutral (Rear Propel Pump)" for adjustment of the swashplate in the NEUTRAL position.

2. Perform the following procedure before you follow the test procedure:
   • Park the machine on a level area that is clear from equipment and material.

   • Verify that the service brake system and the parking brake system are in good working order.

   • Block the drive wheels in both directions.

   • Move the propel lever to the NEUTRAL position.

   • Apply the parking brake.

   • Make sure that the hydraulic oil is at the correct operating temperature.

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Illustration 1	g00894234

3. Remove the access panel that is located on the operator side of the machine.

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Illustration 2	g00915203
Bottom View of Rear Propel Pump (1) Rear propel pump (2) Neutral adjustment locknut (3) Neutral adjustment screw (4) Pressure port "M5"

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Illustration 3	g00915310
Top View of Rear Propel Pump (5) Pressure port "M4" (6) EDC Control connection

4. Assemble the 8T-0857 Pressure Gauges with the proper fittings from the 8T-5320 Hydraulic Test Fitting Group .

5. Remove the plugs at gauge port "M4" (5) and gauge port "M5" (4) .

6. Install the 6V-3965 Fitting Assemblies into gauge port "M4" (5) and gauge port "M5" (4) .

7. Assemble 8T-0857 Pressure Gauges into gauge port "M4" (5) and gauge port "M5" (4) .

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Illustration 4	g00909963
Front View of Rear Propel Pump

8. Disconnect the electronic displacement control from rear propel pump (1) .

   Note: As the EDC is disconnected, a fault will appear on the AVSpare Monitoring System. Reset the system after the test and adjust procedure is complete.

9. Start the engine. Run the engine at normal idle.

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Illustration 5	g00915330
Bottom View of Rear Propel Pump (2) Neutral adjustment locknut (3) Neutral adjustment screw

10. Loosen locknut (2) on neutral adjustment screw (3) .

11. Turn neutral adjustment screw (3) until the system pressure at gauge port "M4" (5) and gauge port "M5" (4) are as close to equal as possible.

12. Turn neutral adjustment screw (3) clockwise. This should be done until one of the gauges registers an increase in system pressure.

    Note: Ensure that the position of the neutral adjustment screw is noted during this adjustment. This may be done by placing a mark on the pump or by recording the angular position of the wrench.

13. Turn neutral adjustment screw (3) counterclockwise. This should be done until the other gauge registers an increase in system pressure.

    Note: Ensure that the position of the neutral adjustment screw is noted during this adjustment. This may be done by placing a mark on the pump or by recording the angular position of the wrench.

14. Rotate the neutral adjustment screw for half of the distance between the locations that are noted above. Observe the pressure of both gauges. Both gauges should have close to equal pressure. This will indicate that the NEUTRAL position is set.

15. Hold adjustment screw (3) stationary. Tighten adjustment locknut (2) .

    Note: If adjustment screw (3) turns as adjustment screw locknut (2) is tightened, repeat Steps 10 through Steps 14.

16. The neutral adjustment is set.

17. Reconnect the electric displacement control. Clear any faults that may appear on the AVSpare Monitoring System.

Note: The following steps are optional, but will ensure overall accuracy for setting the NEUTRAL position for the EDC control. The following steps should only be performed after the NEUTRAL position is set. The following steps are secondary only and not to be used in place of the main test listed above.

18. Ensure the information in Step 2 is still understood. Refer to the warnings that are located at the beginning of this test and heed the warnings that are located at the beginning of this test.

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Illustration 6	g00915419
The Manual Override for the EDC Control is Located to the Rear of the Rear Propel Pump. (7) Override in the REVERSE position (8) Override in the FORWARD position (9) Stationary or NEUTRAL position

19. Keep your foot readily available to depress the service brake as the assistant performs this test.

20. Move manual override knob slowly to REVERSE position (7). There should be input signal pressure that will the pump on stroke in the REVERSE position. Immediately release the manual override knob and the system will return to the stationary NEUTRAL position (9) .

21. Move manual override knob slowly to FORWARD position (8). There should be input signal pressure that will bring the pump on stroke in the FORWARD position. Immediately release the manual override knob and the system will return to the stationary NEUTRAL position (9) .

22. Apply the service brake

    Note: This secondary test will confirm that the EDC control is the NEUTRAL position.

23. Shut off the engine.

24. Observe the machine and the operating temperature. Fifteen minutes should pass before you proceed to the next steps. This will also allow the pressure in the system to bleed down. Refer to the warnings at the beginning of this test.

25. Remove the pressure gauges from pressure gauge port "M4" (5) and pressure gauge port "M5" (4) .

26. Remove the 6V-3965 Fitting Assemblies. Install the plugs into pressure gauge port "M4" (5) and pressure gauge port "M5" (4) .

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Illustration 7	g00894234

27. Reconnect the access panel to the machine.