Attention! On a vehicle with a diesel engine, the vacuum is created by a specially installed vacuum pump.
Vacuum-type brake booster is designed to create additional force applied to the rod of the main brake cylinder. If unusually high pedal force is required to achieve sufficient braking, the brake booster vacuum should be checked.
The amplifier must be checked in the following order. Remove heater baffle and install tool «34.3.100» (pic. 11.50) between the handpiece and the vacuum hose coming from the check valve.
Start the engine and check that the vacuum builds up (pressure drops). Stop the engine.
Pressing the brake pedal with a force of 200 N (20.0 kgf), create a vacuum of no more than 0.8 bar and wait until the value stabilizes. With the brake pedal not depressed, the vacuum may drop during the test by no more than 0.06 bar per 1 minute.
If the indicators deviate from the above values, it is necessary:
- check the tightness of the hose connections;
- replace check valve.
- check the condition and tightness of the gasket (rings) between the brake booster and the master brake cylinder;
- re-calibrate, if the specified values are not reached, it is necessary to replace the brake booster.