Hydraulic System: Description and Operation

Hydraulic Brake Actuation

Hydraulic Brakes

The hydraulic brake actuation system consists of the following components:

- Brake master cylinder and fluid reservoir

- Brake tubes and hoses

- Brake pedal and bracket

- Hydraulic Control Unit (HCU)

The brake pedal is connected to the power brake booster, which is connected to the brake master cylinder. When the brake pedal is pressed, brake fluid is forced through the double-walled steel tubes and flexible hoses to the HCU (Hydraulic Control Unit). The brake fluid is then distributed to the front and rear brake calipers. The fluid enters the caliper, forcing the caliper pistons and brake pads outward against the brake disc friction surface, slowing or stopping rotation of the brake disc. When the brake pedal is released, brake fluid pressure is relieved, returning the front and rear brake caliper pistons and brake pads to the unapplied position.

The hydraulic brake system is diagonally split with the LH front and RH rear brakes on one circuit and the RH front and LH rear brakes on the other circuit.

For information on the HCU (Hydraulic Control Unit), refer to Antilock Brakes/Traction Control Systems.

Adjustable Pedals With Memory Feature

The brake pedal position can be changed in phase with the accelerator pedal to increase driver comfort.

Adjustable brake pedals with memory feature consist of the following components:

- Driver Seat Module (DSM), refer to Seats

- Memory SET switch, refer to Seats

- Remote Keyless Entry (RKE) transmitter, refer to Doors, Hood and Trunk &/or Locks.

- Adjustable brake pedal and bracket

- Adjustable accelerator pedal and bracket, refer to Fuel Delivery and Air Induction

- Adjustable pedal switch

- Adjustable pedal motor

- Adjustable pedal cables

The adjustable pedals with memory feature are controlled by the Driver Seat Module (DSM) and can be adjusted in 3 different ways:

- Using the adjustable pedal switch

- Using the memory SET switch

- Using the Remote Keyless Entry (RKE) transmitter

When the switch is pressed or the transmitter is activated, the DSM (Driver Seat Module) activates the adjustable pedal motor to move the brake and accelerator pedal in the commanded direction.