PC404 Cold Planer Caterpillar

Preparation for Troubleshooting

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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 hydraulic system.

1. Park the host machine on a smooth, level surface. Move away from other operating machines and away from personnel. Lower the work tool to the ground. Stop the engine.

2. Permit only one operator on the host machine. Keep other personnel away from the host machine or in the operator's sight.

3. Engage the parking brake. Place chocks in front of the wheels and behind the wheels.

4. When the work tool is raised for testing or for adjusting, make sure that the work tool is supported correctly. The lift circuit has high oil pressure when the lift arms raise the work tool.

   Note: Do not stop the host machine with the work tool off the ground unless this is required for a test. Lower the work tool to the ground and stop the engine.

5. Cycle the hydraulic control levers through all positions in order to release the pressure in the hydraulic system.

6. To relieve all of the pressure in the hydraulic oil tank, slowly loosen the filler cap.

   Note: All hydraulic pressure must be released before any hydraulic components are worked on.

7. Install the filler cap.

During a diagnosis of the hydraulic system, remember that correct oil flow and correct pressure are necessary for correct machine operation. The pump output increases as the engine speed increases and vice versa. Oil pressure is caused by resistance to the flow of oil.

Visual Inspection

A visual inspection of the hydraulic system is the first step when you troubleshoot a problem. The inspection should be made with the engine off. Lower the work tool to the ground.

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

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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.

1. Check the level of the oil in the hydraulic tank. Slowly loosen the fill/vent plug and release the pressure before the fill/vent plug is removed.

2. Remove hydraulic filter elements and check for material that would give an indication of damage to a component.

3. Inspect all lines and connections for damage or leaks.

4. Inspect all appropriate switches for damage, loose connections, and broken wires.

Operational Checks

Operate the work tool at different engine speeds. Note the noises that are not normal and find the sources of the noises. If the work tool is not operating properly, refer to the following troubleshooting problem list.

Verify that the hydraulic system of the host machine is functioning properly. Refer to the Testing and Adjusting procedures of the host machine.

Troubleshooting Probable Causes

Problem 1

The motor for the cold planer will not operate.

Probable causes

1. The manifold for the check valve is installed incorrectly on the motor.

2. The hydraulic hoses are not properly connected to the host machine.

3. The hydraulic hoses on the host machine are obstructed.

4. The hydraulic hoses on the cold planer are obstructed.

5. The motor has failed.

6. The valve on the host machine that supplies oil to the cold planer is faulty.

Problem 2

Sluggish drum rotation

Probable causes

1. Insufficient hydraulic oil flow from the host machine

2. One or more seals have failed in the motor.

3. The hydraulic oil filter on the host machine is dirty.

4. The check valve is not seated correctly.

Problem 3

The motor operates but the drum does not rotate.

Probable causes

1. The hub has a sheared key.

Problem 4

Oil leaks from the motor.

Probable causes

1. One or more seals have failed in the motor.

2. Seals on the fittings are damaged.

3. Fittings are loose or damaged.

4. The seal for the manifold for the check valve has failed.

5. The manifold for the check valve is not tightened properly.

6. The hydraulic hoses are loose or damaged.

Problem 5

Insufficient cutting power

Probable causes

1. The hydraulic oil filter on the host machine is dirty.

2. Insufficient hydraulic oil pressure from the host machine

3. The relief valve on the host machine is damaged or the relief valve on the host machine is not adjusted properly.

4. One or more seals have failed in the motor.

5. The check valve is stuck open.

Problem 6

Excessive hydraulic oil temperature

Probable causes

1. Low hydraulic oil level on the host machine

2. The hydraulic hoses are obstructed.

3. The hydraulic oil is dirty.

4. The relief valve on the host machine is not adjusted properly.

Problem 7

The drum of the cold planer rotates in the wrong direction.

Probable causes

1. The manifold for the check valve is not installed correctly.

Problem 8

The drum of the cold planer rotates in both direction.

Probable causes

The check valve is stuck in the closed position.