Repair and replacement of clutch master cylinder

Cars with manual transmissions after a large run may have problems in the clutch unit, of which the clutch master cylinder is often the cause. Works on its replacement can be carried out by masters at almost any service station. However, the cost of the operation is unlikely to please the car owner.

In order to restore the health of this site did not cause unnecessary financial costs, it is enough to purchase a clutch master cylinder repair kit and do the replacement work yourself. It will not cause great difficulties, but it will save money.


  • 1 Clutch Cylinder Functions
  • 2 VAZ design
  • 3 dismantling process
  • 4 Clutch bleed
  • 5 Conclusion

Clutch Cylinder Functions

The quality of work of this unit in the car affects the long-term operation of the gearbox, the speed and smoothness of switching between the gearbox stages. The main task of the mechanism is to connect / disconnect the rotation of the motor between the driver’s gearshifts.

Proper grip features quiet operation.

Driving gears in the gearbox have time to get out of gearing for shifting. If the mechanism is faulty, the process occurs with a characteristic rasp. Such “unclean” work can be with incomplete squeezing or a faulty clutch.

what the clutch master cylinder looks like

Audi clutch master cylinder

In case of poor-quality work of the unit, the clutch master cylinder will need repair. If this is not done, the box will quickly fail, the gear teeth will sprinkle or develop. Replacing gearbox cost much more. Trouble with the box may occur while the vehicle is moving, gears may be jammed and the driver will not be able to change to another degree. These actions may lead to an emergency.

After identifying the cause of the malfunction, it is necessary to replace the clutch master cylinder so as not to aggravate the situation. An additional sign by which to judge this problem is frequent "hang" clutch pedal in extreme position. It even happens that the liquid flows down the pedal into the car.

VAZ design

"Classic" cars VAZ have in their design a hydraulic clutch, which is formed from a pair of cylinders: working (RC) and main (HZ). A driver acts on HZ by depressing the pedal. At this time, an overpressure is generated, which transfers to the RC, moving the working shift fork. The main one is located above, and the worker is below.

You need to know that in models 2101-2107 and their modifications, this unit retained the design unchanged, so before you remove the clutch master cylinder, you must purchase a new one, which will indicate any “classic” model.

The unit uses normal brake fluid as the working fluid.

See also: How to check the health of CV joints

Dismantling process

First, the tank is disconnected. Next, free the clamp on the HZ and turn it so that excess liquid does not flow. Unscrew the pipe going to the RC. This is done with the help of a special key, which can be bought at any auto shop.

how the clutch master cylinder is repaired
Step 1. Remove the protective cap
how to disassemble the clutch master cylinder
Step 2. Remove the lock washer
how to choose a clutch master cylinder repair kit
Step 3. We get the union
how to repair clutch master cylinder
Step 4. Unscrew the cork
where to start repairing clutch master cylinder
Step 5. Remove the puck with a stripper
clutch master cylinder device
Step 6. We get the contents of the cylinder

After that, unscrew the two nuts at 13. They fix the HZ. Now HZ can be taken out. We clean the cylinder of dirt to continue to work with clean parts. To do this, it must be washed.

You need to know that gasoline is not allowed to wash the master cylinder. This causes the rubber parts to corrode. It is necessary to use new brake fluid.

Чтобы увидеть clutch master cylinder device, надо высвободить стопорное кольцо. Делать это можно с помощью шила или специального съемника. Removing the inner contents must be carefully, as the mechanism contains a spring.

Scratching the case with metal objects, including a screwdriver, is not worth it, because the surface may be damaged. It is necessary to clean only with rags and brake fluid.

Old rings must be changed, even if they look slightly worked out. Also, thoroughly clean all grooves of possible dirt. The assembly process consists of reverse disassembly operations. In the last stage, a new retaining ring is installed.

Clutch bleed

Assembled and installed cylinders must be filled with working fluid without air traps. To do this, you need to properly pump the clutch. There are several options for performing such an operation.

how to replace the clutch master cylinder

Dismantling the clutch master cylinder

In the first case the tank is filled with a sufficient amount of fluid. Next, unscrew the nozzle, which is installed specifically for the pumping process, and put on the end of the flexible tube. The second side is lowered into the container under the car. Now you can press the pedal and thereby release excess air from the hydraulic system. Do not forget to regularly add fluid to the tank during this process. After all the air comes out, tighten the fitting.

See also: Changing the oil in the gearbox mechanic

In the second case We use the help of a partner. His actions consist of pumping the clutch pedal 5-6 times until it stops, and then clamping it in the extreme position. At this time, you can unscrew the fitting and release excess air. After the gas is out, the partner repeats his actions, and the owner bleeds again. The process is carried out until the gas stops flowing, and the pedal will work normally. This usually happens after several such “work” cycles.

Third option does not always work well, but can also be applied. At the same time the liquid is poured into the tank, and the fitting is open at this time. When it passes by gravity throughout the system, it must displace excess air. A sign of the end is stable flow without visible bubbles.


Work on the replacement or repair of the clutch master cylinder is quite capable of carrying out independently. To do this, you need a repair kit that fits your car model and a working clean brake fluid. The latter is used as a wash and for filling the system after repair.