LeSabre V6-181 3.0L (1986)
Hydraulic Brake Booster: Description and Operation
The Booster assists the driver's foot pressure on the brake pedal. It also applies hydraulic pressure to the rear channel directly (during both
non-antilock and antilock braking).
The Booster applies hydraulic pressure to the front channels through the booster piston (during non-antilock braking) or directly through the main
valve (during antilock braking). The booster control valve allows fluid under pressure to enter the booster chamber. The control valve regulates the
amount of pressure, based on brake pedal force. This allows the driver to control the stopping of the vehicle with a sense of "feel." The booster piston
pushes the master cylinder piston(s). Brake pedal force and booster hydraulic pressure operate the master cylinder during non-antilock braking. The
driver can directly apply the front brakes mechanically if the booster malfunctions. During service, technicians can use the booster as a pressure
bleeder for the rear hydraulic channel. In order to bleed the LF and RF hydraulic channels, use conventional pressure or manual techniques.
