Reasons why the Hydraulic clutch is not completely separated

There are a number of possible reasons why the Hydraulic clutch is not completely separated. These include mechanical problems with the clutch itself, faults in the hydraulic system and the associated effects of other parts of the vehicle. The following are some of the possible causes:

1. Clutch pedal free travel problem:

Too much or too little free travel of the clutch pedal may result in incomplete clutch disengagement. When the free travel is too large, the clutch pedal working stroke will be reduced accordingly, resulting in insufficient backward movement of the pressure plate to completely release the pressure force on the driven disc, thus leaving the clutch in a semi-disengaged state.

- Pedal free travel is too large: the free travel of the clutch pedal is improperly set so that the release mechanism may not be fully activated even if the pedal is depressed.

2. Problems with the release lever and support:

The release lever may be bent and deformed, the support loosened, the shaft pin hole worn through or the shaft pin stripped out, etc., resulting in the contact surface between the release lever and the release bearing being of different heights, which affects the normal disengagement of the clutch.

3. Clutch disc problem:

The slave disc may have warping, broken steel plate, uneven friction surface, or the replacement friction lining is too thick, the slave disc or the middle pressure plate is wrongly installed on the front and back, etc. All these will lead to the clutch not being able to be fully disengaged.

4. Failure of hydraulic system:

The work of the hydraulic clutch depends on the stable oil supply of the hydraulic system. If there is oil leakage, air leakage or insufficient oil in the hydraulic system, or if the clearance between the master cylinder piston and push rod is not properly adjusted, it will lead to low working oil pressure, which in turn will affect the clutch disengagement effect.

   - Insufficient oil: The oil in the clutch oil pot is too low, resulting in insufficient hydraulic pressure.

   - Oil leakage: Damaged oil pipes, joints or seals of the clutch master pump or sub-pump, resulting in hydraulic oil leakage.

   - Oil pump failure: The oil pump is damaged or worn and cannot provide sufficient pressure.

   - Clogged oil line: internal oil line or screen is clogged, affecting the flow of hydraulic oil.

5. Clutch disc wear:

   - Excessive wear of the clutch friction disc, resulting in the pressure disc not being able to completely separate from the flywheel even at maximum pressure.

6. Problems with the pressure disc or release mechanism:

   - Pressure disc spring attenuation: The spring force of the pressure disc spring is weakened and cannot effectively push the pressure disc to separate.

   - Separation bearing wear: The separation bearing is worn or damaged, affecting its ability to push the separation lever.

7. mechanical connection problems:

   - Deformation of the release lever or linkage: the release lever is bent or its connection is loose, affecting the efficiency of the release.

   - Assembly error: incorrect installation of the clutch assembly, e.g. wrongly installed slave disc, may result in failure to fully disengage.

8. Other component related effects:

Problems such as wear or damage to the engine mounts, or non-centricity of the engine and transmission, may also result in incomplete clutch disengagement. In addition, the front bearing of the first shaft of the transmission is poorly lubricated and bites, which can also cause the engine to drag the transmission directly, affecting the normal operation of the clutch.

   - Rust or contamination: Rust or foreign matter in the clutch system may cause moving parts to seize.

   - Transmission problems: If the first shaft bearing is damaged, it may indirectly affect clutch disengagement.

How can I solve the problem of incomplete hydraulic clutch disengagement?

The solution to the problem of incomplete hydraulic clutch disengagement can be found in the following areas:

1. Check and adjust the clutch pedal freewheeling stroke

Cause: Incomplete clutch disengagement can be caused by either too much or too little free travel of the clutch pedal. When the free travel is too large, the working stroke of the clutch pedal will be reduced accordingly, resulting in insufficient backward movement of the pressure disc, which cannot completely release the pressure force on the driven disc.

Solution: Measure the free travel of the clutch pedal and adjust it according to the vehicle manufacturer's specifications. Ensure that the free travel is within reasonable limits to ensure that the clutch can be fully disengaged.

2. Check the release lever and support

Cause: The release lever may be bent and deformed, the support loosened, the shaft pin hole worn through or the shaft pin stripped out, etc., resulting in the contact surface between the release lever and the release bearing being of different heights, thus affecting the normal disengagement of the clutch.

Solution: Carry out a careful inspection of the release lever and support to confirm whether they are deformed, loose or worn. If there is any problem, it needs to be repaired or replaced. At the same time, check and adjust the height of the release lever to ensure that it is in the same plane.

3. Check the clutch disc and pressure plate.

Cause: The clutch disc may be warped, the steel plate broken, the friction surface uneven, etc., or the pressure plate loose, deformation, will lead to the clutch can not be completely disengaged.

Solution: Remove the clutch and carefully inspect the disc and pressure plate. If you find that the driven disc is warped, broken or the friction surface is uneven, it needs to be replaced. At the same time, check whether the pressure plate is loose or deformed, if necessary, also need to be repaired or replaced.

4. Check the hydraulic system

Reason: The operation of the hydraulic clutch depends on the stable oil supply of the hydraulic system. If there is oil leakage, air leakage or insufficient oil in the hydraulic system, it will affect the clutch disengagement effect.

Solution: Check the piping, joints and seals of the hydraulic system to make sure there is no oil or air leakage. At the same time, check the oil level and quality of the hydraulic oil to ensure that the oil quantity is sufficient and the oil quality is good. If there is any problem, it is necessary to replenish or replace the hydraulic oil in time and repair the oil or air leakage parts.

5. Check and adjust other related parts

Cause: Wear or damage of the engine bracket, different concentricity of the engine and transmission and other problems may also lead to incomplete clutch disengagement.

SOLUTION: Check whether the fixing bolts of the engine bracket are loose or worn, and tighten or replace them if necessary. At the same time, check the connection between the engine and transmission to make sure they are concentric.

6. Seek professional maintenance assistance

If none of the above methods solves the problem, or you do not have the relevant repair skills and tools, it is recommended that you visit a professional auto repair shop for inspection and repair. A professional mechanic will be able to diagnose the problem more accurately and take appropriate measures to repair it.

Please note that since the structure and mechanism of the clutch is relatively complex and requires professional repair skills and tools for overhaul and maintenance, it is recommended that you visit a professional auto repair shop for inspection and repair in a timely manner when you encounter the problem of incomplete clutch disengagement.   

In summary, to solve the problem of incomplete hydraulic clutch disengagement, it is necessary to comprehensively consider a number of aspects, starting from the free travel of the clutch pedal, the release lever and support, the clutch disc and pressure plate, the hydraulic system, and other related components, etc. for inspection and adjustment.