Brakes and Traction Control: Description and Operation

Brake System
The brake system consists of the following components:
^ ABS hydraulic control unit (HCU)
^ Vacuum booster power booster (E-150 to E-350 single rear wheel [SRW])
^ Hydro-Boost(R) power booster (E-350 and E-450 dual rear wheel [DRW])
^ Master cylinder
^ Front brake discs
^ Rear brake discs
^ Parking brakes

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 pushed through the doubled-walled steel tubes and flexible hoses to the front and rear disc brake calipers. The brake fluid enters the disc brake calipers, forcing the caliper pistons and brake pads outward against the brake disc friction surface, slowing or stopping rotation. When the brake pedal is released, brake fluid pressure is relieved, returning the front and rear disc brake caliper pistons and brake pads to the unapplied position.

For information on:
^ the brake pedal, refer to Hydraulic System, Brakes.
^ ABS and HCU, refer to Antilock Brakes / Traction Control Systems.
^ the master cylinder and fluid reservoir, refer to Hydraulic System, Brakes.
^ The brake power assist is vacuum-operated on the E-150, E250 and E-350 SRW. The E-350 and E-450 DRW are equipped with a Hydro-Boost(R) power brake booster powered by the power steering pump. Refer to Power Brake Assist.
^ the brake calipers, refer to Disc Brake System.
^ the drum-in-hat integrated parking brake system, refer to Parking Brake System.