BMW 3 series E46

Since 1998 of release

Repair and car operation

Check of the amplifier of a brake

Check up work of the amplifier of a brake if for achievement of necessary braking it is required to put excessively big effort to a brake pedal.

1 At the idle engine press a pedal of a brake not less than 10 times, then at the pressed pedal start the engine. Now the brake pedal should move aloud. In this case the amplifier is serviceable.
2 Otherwise disconnect a vacuum hose at the amplifier and start the engine. Put a finger to the end of a hose and check up, whether there is a vacuum.
3 If the vacuum is not present: Check up a vacuum hose on tightness and presence of damages, if necessary replace it. Tighten fastening of all collars.
4 Diesel engine: Disconnect a vacuum hose from the vacuum pump and check up a finger, whether there is a vacuum. The vacuum pump is fixed to a head of cylinders.
5 If the vacuum is available: Measure value of vacuum, if necessary replace the brake amplifier (work HUNDRED).

At the petrol engine necessarily replace also the return valve in the vacuum pipeline as the diaphragm in the brake amplifier at the faulty return valve owing to getting steams of fuel can be damaged.