Location of the vacuum booster (spare tire removed): 1 - vacuum booster; 2 - master brake cylinder; 3 - vacuum hose; 4 - check valve.
You will need: Screwdriver, rubber bulb.
Before starting work, remove the spare tire.
When the vacuum booster fails, the force on the brake pedal increases significantly, which negatively affects vehicle control.
If you are unable to eliminate the defects associated with the operation of the vacuum booster, contact specialists.
With the engine off, press the brake pedal 5-6 times. Keep the brake pedal depressed and start the engine. The brake pedal should move forward. If this does not happen, check...
...the tightness of the vacuum hose fit on the intake pipe fitting and...
...on the check valve. If necessary, depending on the defect, tighten the hose clamp, replace the clamp or the hose.
To check the check valve, disconnect the vacuum hose from the valve.
Remove the valve from the amplifier body.
Put it on a larger diameter nipple (which the valve is inserted into the amplifier) rubber bulb and squeeze it. In doing so...
...the air should come out through the valve. Release the bulb. If it remains compressed, the valve is OK. Otherwise, replace the valve. If there is no bulb, you can blow through the valve with your mouth.
The original can be found on the website [VazBook]