Attention! In a vehicle with a diesel engine, the vacuum is created by a specially installed vacuum pump.
The brake booster is a vacuum type, designed to create additional force applied to the main brake cylinder rod. If an unusually large force on the pedal is required to achieve sufficient braking, then it is necessary to check the brake booster.
The amplifier must be checked in the following order: Remove the heater partition and install the device "34.3.100" (fig. 11.50) between the tip and the vacuum hose coming from the check valve.
Start the engine and make sure that the vacuum increases (the pressure is dropping). Turn off the engine.
Press 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. When the brake pedal is not pressed, the vacuum is allowed to drop during the test by no more than 0.06 bar in 1 min.
If the indicators deviate from the above values, it is necessary:
- check the tightness of the hose connections;
- replace the check valve.
- check the condition and tightness of the sealing gasket (ring) between the brake booster and the master brake cylinder;
- conduct a re-check; if the specified values are not achieved, the brake booster must be replaced.