LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2004 >> ML500 >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Brakes -- 163 Chassis >> Basic Knowledge >> BAS function in normal operation - GF42.31-P-3000A

BAS function in normal operation - GF42.31-P-3000A

MODELS 129,140 as of 1.12.96, 210 as of 1.2.97, 170, 202 as of 1.6.97, 168 up to 28.2.01, 163, 203, 208, 209, 215, 220 

Brake application in normal operation 

The BAS brake booster (A7/7) is supplied continuously via the vacuum line with inlet manifold vacuum or pump vacuum on diesel models. If the brake is not actuated, equal vacuum exists on both sides of the diaphragms. The compression spring holds the vacuum piston in its starting position.

On brake application, atmospheric air is fed to the back of the diaphragms via a duct. A pressure difference that increases with the braking is created between the front and rear chambers of the booster and the resulting force acts in the direction of the master brake cylinder and supplements foot pressure.

Illustration shows partial braking

Fig 1: Locating BAS Brake Booster
G04607223
  BAS pressure increase function   GF42.31-P-3100A 
  BAS pressure reduction function   GF42.31-P-3200A 
  BAS brake booster, location / task / design / function   GF42.31-P-4000A 
  BAS control module, location / task / function   GF42.31-P-4500A