525C, 535C and 545C Wheel Skidders Grapple Caterpillar

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.

This test will help to determine whether the arch cylinder or the boom cylinder is causing a drift problem. If either cylinder moves, there may be internal leakage in the arch cylinder or the boom cylinder.

Arch Cylinders

1. Move the transmission direction control switch to the NEUTRAL position.

2. Engage the parking brake.

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Illustration 1	g00526560
Steering Frame Lock in the LOCKED Position

3. Move the steering frame lock to the LOCKED position.

4. Start the engine. Warm the hydraulic oil to normal operating temperature of approximately 40 to 55°C (104 to 130°F).

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Illustration 2	g01210648
Grapple Control Lever

5. Fully extend the arch cylinders at least five times by moving the grapple control lever forward and backward. Retract the arch cylinder 100 mm (4 inch) from the fully extended position.

6. Run the engine at low idle.

7. Check the distance of the rod movement in five minutes. For a new cylinder, the maximum rod movement in five minutes is 30.0 mm (1.18 inch).

8. If the amount of cylinder drift is within the specification, proceed to Step 11.

9. If the cylinder drift exceeds the specification, check the following possibilities.

   1. Check the line relief/makeup valve in the arch control valve.

   2. Check the condition of the valve spools in the arch control valve.

   3. Check the seals in the arch cylinders.

   4. Check the pilot valve for leakage.

   5. Check the selector and pressure control valve for leakage.

10. Repeat Steps 4 through 8 after making adjustments.

11. Lower the grapple to the ground. Turn the "engine start key" to the OFF position.

Boom Cylinders

1. Move the transmission direction control switch to the NEUTRAL position.

2. Engage the parking brake.

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Illustration 3	g00526560
Steering Frame Lock in the LOCKED Position

3. Move the steering frame lock to the LOCKED position.

4. Start the engine. Warm the hydraulic oil to normal operating temperature of approximately 40 to 55°C (104 to 130°F).

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Illustration 4	g01210648
Grapple Control Lever

5. Fully extend the boom cylinders at least five times by moving the grapple control lever to the left and to the right. Retract the boom cylinder 100 mm (4 inch) from the fully extended position.

6. Run the engine at low idle.

7. Check the distance of the rod movement in five minutes. For a new cylinder, the maximum rod movement in five minutes is 30.0 mm (1.18 inch).

8. If the amount of cylinder drift is within the specification, proceed to Step 11.

9. If the cylinder drift exceeds the specification, check the following possibilities.

   1. Check the line relief/makeup valve in the boom control valve.

   2. Check the condition of the valve spools in the boom control valve.

   3. Check the seals in the boom cylinders.

   4. Check the pilot valve for leakage.

   5. Check the selector and pressure control valve for leakage.

10. Repeat Steps 4 through 8 after making adjustments.

11. Lower the grapple to the ground. Turn the "engine start key" to the OFF position.