Checking the brake booster
To check the brake booster, start the engine and let it run for one or two minutes, then turn off the engine
After that, press the brake pedal several times with normal force
If the pedal goes down the first time you press it, but gradually rises the second and third time you press it, the booster is working properly.
If the pedal height does not change, the booster is faulty.
With the engine off, press the brake pedal several times and check for a change in pedal height
After that, press the pedal and start the engine.
If the pedal goes down a little, the booster is working properly.
If the pedal height remains the same, the booster is faulty
With the engine running, press the brake pedal and stop the engine.
Hold the pedal down for thirty seconds.
If the pedal height does not change during this time, the booster is working properly. If the pedal rises, the booster is faulty
If one of the above methods of checking reveals a fault, you need to check the vacuum hose and booster and fix the fault.
Checking the vacuum hose valve
Disconnect the vacuum hose (A) from the vacuum booster
Start the engine and set the idle speed.
A vacuum should appear on the side of the disconnected end of the hose. If there is no vacuum, then the valve is not working.
Replacing the brake booster
Disconnect the vacuum hose (B) from the brake booster housing (A)
Unscrew the mounting nuts and remove the brake master cylinder
Disconnect the vacuum hose from the booster
Unscrew the four mounting nuts of the vacuum booster
Remove the vacuum booster (A) from the car
Installation
Before installation, adjust the length of the vacuum booster rod, then install the gasket on the booster body.
Standard rod length (A): 108±0.5 mm.
Install the booster and tighten the mounting nuts (C) to the required tightening torque
Connect the booster rod to the brake pedal by installing the pin (A) and the locking pin (B) on the pin (A).
Before installing the locking pin, apply grease to the pin
Install the master brake cylinder.
Then we connect the brake pipes to the master cylinder
We connect the vacuum hose to the booster
We fill the brake fluid into the expansion tank of the master cylinder and bleed the brake hydraulic drive
We check the system for brake fluid leaks
We check the free and working travel of the brake pedal, if necessary, adjust we are ruem.