D3G, D4G and D5G Track-Type Tractors Electrohydraulic Power Train Systems Caterpillar

• The pump has been rebuilt.

• A track starts to turn when the speed and direction control is in the NEUTRAL position and the pump has been calibrated.

This adjustment requires a mechanical adjustment and a hydraulic adjustment. You must perform the mechanical adjustment before you perform the hydraulic adjustment.

Refer to Testing and Adjusting, "Tooling Preparation" for additional information for tooling assembly and for alternate methods of testing.

Mechanical Adjustment

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Illustration 1	g00798620

1. Remove four bolts (3) and washers.

2. Remove two footrests (1) .

3. Remove floormat (2) .

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Illustration 2	g00798650

4. Remove six bolts (4) and washers.

5. Remove access panel (5) .

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Illustration 3	g00836976

6. Install vacuum cap (8) onto hydraulic tank (9) .

7. Connect hose (7) to vacuum cap (8). Route the other end of the hose into a suitable container in order to collect any oil that may drain from the hose.

8. Connect air hose (6) to vacuum cap (8) .

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Illustration 4	g00840289

9. Remove the plug (10) from the "X1" port and remove plug (11) from the "X2" port.

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Illustration 5	g00840290

10. Install a nipple assembly (12) for each port.

11. Disconnect air hose (6) .

12. Connect one end of a hose assembly to the "X1" port and connect the other end of the hose assembly to the "X2" port.

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Illustration 6	g00796009

13. Open the access door on the right side of the machine.

14. Connect a tetragauge to the pressure tap for the pump that is being adjusted.
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    Illustration 7	g00838526

    1. Connect a tetragauge to pressure tap"1" if you are adjusting the rear pump.
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    Illustration 8	g00838527

    2. Connect a tetragauge to pressure tap "2" if you are adjusting the front pump.

15. Enter the machine.

16. Start the engine.

17. Allow the oil to warm up to a minimum temperature of 20 °C (68.0000 °F).

18. Use the Electronic Technician (ET) to set the machine to STALL TEST MODE. Refer to Testing and Adjusting, "Transmission Stall - Set".

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Illustration 9	g00909547

19. Mark the initial position of set screw (14) .

20. Loosen locknut (13) on set screw (14) .

21. Turn the set screw clockwise until the drive loop pressure increases by 200 kPa (30 psi). Mark this position.

22. Turn the set screw back to the original position.

23. Turn the set screw counterclockwise until the drive loop pressure increases by 200 kPa (30 psi). Mark this position.

24. Position the set screw at the midpoint between the two positions that were marked in Step 21 and Step 23.

25. Maintain the position of set screw (14) while you tighten locknut (13) .

26. Stop the engine.

27. Remove the jumper hose between the two ports.

28. Remove the tetragauge from the pressure tap.

Hydraulic Adjustment

1. Install a hose assembly onto the "X1" port and install a hose assembly onto the "X2" port.

2. Install a 8T-0856 Gauge Assembly (0 to 6,000 kPa (0 to 870 psi)) onto the end of each hose assembly.

3. Start the engine.

4. Use the Electronic Technician (ET) to set the machine to STALL TEST MODE. Refer to Testing and Adjusting, "Transmission Stall - Set".

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Illustration 10	g00909551

5. Loosen lock screw (16) for set screw (15) .

6. Adjust the set screw until the pressure at the "X1" port is within 200 kPa (30 psi) of the pressure of the "X2" port.

7. Maintain the position of the set screw while you tighten the lock screw.

Note: This adjustment is sensitive and the adjustment can easily change as you tighten the lock screw.

8. Verify that the pressures of the two ports are within 200 kPa (30 psi) of each other.

   1. Stop the engine.

   2. Exchange the gauges of the two ports.

   3. Start the engine.

   4. Verify that the pressures of the two ports are within 200 kPa (30 psi) of each other.

   5. Stop the engine.

9. Remove the gauges and hoses.

10. Remove the nipple assemblies and reinstall the plugs.

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Illustration 11	g00798650

11. Install the access panel (5) .

12. Install six bolts (4) and washers.

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Illustration 12	g00798620

13. Install floormat (2) .

14. Align footrests (1) and install four bolts (3) and washers.