1. The vacuum servo is located between the brake pedal and the master cylinder and makes it easier for the driver to press the brake pedal. The block is powered by vacuum from the intake manifold, on some models the vacuum is increased by a vacuum booster in the vacuum supply.
2. The block is mainly composed of a diaphragm and a non-return valve. When the brake pedal is released, vacuum flows to both sides of the diaphragm, but when the pedal is depressed, one side opens to atmosphere. The resulting pressure difference helps push the master cylinder pistons.
3. Usually, the vacuum servo is very reliable, but if the unit still stops working, it must be replaced. Breakdown of the hydraulic system is not affected in any way, except that it is necessary to apply more force to the pedal.
4. To test the vacuum servo, depress the brake pedal several times with the engine off to release the vacuum. Depress the brake pedal moderately, start the engine. The pedal should move slightly down if the servomotor unit is working properly.
Visitor comments