AP-1055D and BG-2455D Asphalt Pavers Auxiliary System Caterpillar

Troubleshooting Problem List

Problem: A hydraulic pump has excessive noise

Probable Cause:

1. The pump is cavitating.

2. There is air in the hydraulic oil.

3. The hydraulic pump has been damaged.

Problem: The hydraulic oil is overheating

Probable Cause:

1. The hydraulic pressure is too high.

2. The hydraulic oil level is low.

3. The hydraulic oil is contaminated.

4. The wrong type of hydraulic oil is being used.

5. The hydraulic oil cooler is plugged.

6. The hydraulic pump is damaged.

Problem: The hydraulic system does not contain any hydraulic pressure

Probable Cause:

1. The hydraulic system does not contain any oil flow.

Problem: The hydraulic system does not have any oil flow

Probable Cause:

1. The hydraulic pump is not receiving any oil.

2. The hydraulic pump is faulty.

3. The hydraulic oil level is low.

4. The hydraulic lines are restricted.

5. The hydraulic system is leaking.

Problem: The hydraulic oil pressure fluctuates

Probable Cause:

1. The hydraulic system contains trapped oil.

2. The hydraulic oil is contaminated.

3. The hydraulic pump is faulty.

Problem: A track does not move in either direction

Probable Cause:

1. The hydraulic oil level is low.

2. The propulsion control is faulty.

3. The charge pressure for the propulsion pump is low.

4. The system pressure is low.

5. The combination valve is faulty.

6. The electronic displacement control (EDC) is faulty.

7. The pressure in the propulsion system is greater than the relief valve setting. The machine is in a speed range that is too high.

8. The load control is in the AUTO position with low engine rpm (less than 2100 rpm).

Problem: A track will move in one direction only

Probable Cause:

1. The propulsion control is faulty.

2. The multifunction valve is faulty.

3. The control valve is faulty.

4. The oil in the servo system of the propulsion pump is contaminated.

Problem: The machine cannot be placed in NEUTRAL

Probable Cause:

1. The propulsion control is faulty.

2. The control valve is faulty.

3. The propulsion pump is faulty.

4. The electrical displacement control (EDC) is not adjusted correctly.

Problem: The system is overheating

Probable Cause:

1. The hydraulic oil level is low.

2. The hydraulic oil cooler is plugged or dirty.

3. The suction filter is clogged.

4. The multifunction valve is faulty.

5. The system pressure is high.

6. There is excessive load on one or more systems.

7. There is a restriction in a line.

8. The oil cooler bypass valve is faulty.

9. The charge pressure is low.

Problem: Response of the propulsion system is sluggish

Probable Cause:

1. The charge pressure is low.

2. The control valve is faulty.

3. The oil is not at operating temperature.

4. The setting for the relief valve is incorrect.

Problem: Charge pressure is low in NEUTRAL, and low during FORWARD and REVERSE operation

Probable Cause:

1. The charge relief valve for the propulsion system is faulty.

Problem: Charge pressure is low during FORWARD and REVERSE operation

Probable Cause:

1. The flushing valve for the propulsion motor is faulty.

Problem: The machine creeps in either direction when the speed control is set at zero

Probable Cause:

1. The pump NEUTRAL position is not properly adjusted.

2. The electrical circuit contains a fault.

3. The parking brake is faulty.