TK1051 Track Feller Buncher Machine Systems Caterpillar

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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 work tools have been lowered to the ground, and the 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.

Note: Use the information in the reference to prepare the machine for this test. Also, use the information in the reference to relieve any hydraulic pressure that may be in the hydraulic system.

Reference: For the correct procedure to prepare the machine for this test, refer to Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.

Reference: For the correct procedure to relieve any hydraulic oil pressure that may be in the hydraulic system, refer to Testing and Adjusting, "Hydraulic System Pressure - Release" for the machine that is being serviced.

The margin pressure is the difference between the pump discharge pressure and the load signal pressure.

Upper Pump

1. Release all hydraulic system pressure.

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Illustration 1	g00785429
Right Side of the Machine

2. Raise the cover for the engine compartment.

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Illustration 2	g00785570
(1) Pressure tap for the upper pump. (2) Load signal port for the upper pump. (3) Upper pump. (4) Pressure tap for the lower pump. (5) Load signal port for the lower pump. (6) Lower pump. (A) Tube assembly.

3. Remove tube assembly (A) from load signal port (2) of upper pump (3) and from load signal port (5) of lower pump (6) .

4. Connect one end of a 6V-3081 Hose Assembly to pressure tap (1) for upper pump (3) .

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Illustration 3	g00785604
(7) Pressure gauge. (8) High pressure port. (9) Pressure differential gauge group. (10) Low pressure port. (11) Hose assembly (pump output pressure). (12) Hose assembly (signal pressure).

5. Attach the unconnected end of the hose assembly to high pressure port (8) of 1U-5796 Pressure Differential Gauge Group (9) .

6. Install 0 to 60000 kPa (0 to 8700 psi) pressure gauge (7) onto high pressure port (8) of pressure differential gauge group (9) .

   Note: Pressure gauge (7) will measure the pump output pressure.

7. Connect a separate 6V-3081 Hose Assembly to low pressure port (10) of pressure differential gauge group (9) .

8. Install a tee with a quick disconnect in load signal port (2) for upper pump (3). Attach the unconnected end of the hose assembly to load signal port (2) for upper pump (3). Disconnect the line for the load signal from the tee on the lower pump. Connect the line to the tee of upper pump (3). Place a cap on the tee of the lower load signal port (5) .

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Illustration 4	g00787316
Main Implement Valve (Top View) (13) Boom control valve.

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Illustration 5	g00786480
Main Implement Valve (Boom Up) (13) Boom control valve.

9. Disconnect the pilot line for the boom up on boom control valve (13). Install a tee with a quick disconnect. Connect pilot line to the tee.

10. Attach a hose assembly to the quick disconnect on the tee. Attach a 4000 kPa (600 psi) gauge to the hose assembly.

11. Start the engine.

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Illustration 6	g00786054
Cab Compartment

12. Shift the hydraulic activation control lever into the UNLOCKED position. All implements should now be operable.

13. Warm the hydraulic oil to normal operating temperature. Normal operating temperature is 55 ± 5°C (130 ± 10°F).

14. Move the engine speed dial to position "10". This is high idle speed for the machine that is being serviced 2200 ± 80 RPM.

15. Slowly move the joystick in order to raise the boom until the pressure gauge at the boom control valve reads 1035 to 1380 kPa (150 to 200 psi). Hold the boom control lever at this position.

16. Record the margin pressure.

    Note: The margin pressure is indicated on pressure differential gauge group (9) .

17. The needle on pressure differential gauge group (9) will bounce between readings, but the margin pressure should stabilize at 1900 kPa (275 psi) to 2100 kPa (305 psi).

18. Lower the boom.

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Illustration 7	g00786482
Main Implement Pump (14) Adjustment screw for the upper pump. (15) Adjustment screw for the lower pump.

19. If the margin pressure is not correct, an adjustment to the adjustment screw for the margin pressure must be made. The adjustment screw for the margin pressure is located on the piston pumps.

20. Move the engine speed dial to low idle. Stop the engine.

21. Adjust setscrew (14) in order to adjust the pump margin pressure setting for upper pump (3). Turn the setscrew clockwise in order to increase the margin pressure. Turn the setscrew counterclockwise in order to decrease the margin pressure.

22. Repeat Steps 11 through 21 until the margin pressure is correct.

23. Relieve the hydraulic pressure. See the reference at the start of this procedure for the correct method.

Lower Pump

1. Release all hydraulic system pressure.

2. Connect the 6V-3081 Hose Assembly to pressure tap (4) for output of lower pump (6) .

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Illustration 8	g00785604
(7) Pressure gauge. (8) High pressure port. (9) Pressure differential gauge group. (10) Low pressure port. (11) Hose assembly (pump output pressure). (12) Hose assembly (signal pressure).

3. Attach the unconnected end of the hose assembly to high pressure port (8) of 1U-5796 Pressure Differential Gauge Group (9) .

4. Install 0 to 60000 kPa (0 to 8700 psi) pressure gauge (7) onto high pressure port (8) of pressure differential gauge group (9) .

   Note: Pressure gauge (7) will measure the pump output pressure.

5. Connect a separate 6V-3081 Hose Assembly to low pressure port (10) of pressure differential gauge group (9) .

6. Attach the unconnected end of the hose assembly to the tee of load signal port (5) for lower pump (6). Cap load signal port (2) for upper pump (3) .

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Illustration 9	g00786480
Main Implement Valve (Boom Up) (13) Boom control valve.

7. Disconnect the pilot line for the boom up. Install a tee with a quick disconnect. Connect pilot line to the tee.

8. Attach a hose assembly to the tee. Attach a 4000 kPa (600 psi) gauge to the hose assembly.

9. Start the engine.

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Illustration 10	g00786054
Cab Compartment

10. Shift the hydraulic activation control lever into the UNLOCKED position. All implements should now be operable.

11. Warm the hydraulic oil to normal operating temperature. Normal operating temperature is 55 ± 5°C (130 ± 10°F).

12. Move the engine speed dial to position "10". This is high idle speed for the machine that is being serviced 2200 ± 80 RPM.

13. Slowly move the joystick in order to raise the boom until the pressure gauge at the boom control valve reads 1035 to 1380 kPa (150 to 200 psi). Hold the boom control lever at this position.

14. Record the margin pressure.

    Note: The margin pressure is indicated on pressure differential gauge group (9) .

15. The needle on pressure differential gauge group (9) will bounce between readings, but the margin pressure should stabilize at 1900 kPa (275 psi) to 2100 kPa (305 psi).

16. Lower the boom.

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Illustration 11	g00786482
Main Implement Pump (14) Adjustment screw for the upper pump. (15) Adjustment screw for the lower pump.

17. If the margin pressure is not correct, an adjustment to the adjustment screw for the margin pressure must be made. The adjustment screw for the margin pressure is located on the piston pumps.

18. Move the engine speed dial to low idle. Stop the engine.

19. Adjust setscrew (15) in order to adjust the pump margin pressure setting for lower pump (6). Turn the setscrew clockwise in order to increase the margin pressure. Turn the setscrew counterclockwise in order to decrease the margin pressure.

20. Repeat Steps 9 through 19 until the margin pressure is correct.

21. Relieve the system hydraulic pressure. See the reference at the start of this procedure for the correct method.

22. Remove all hydraulic test equipment. Connect all lines.