Brake Master Cylinder, Cutaway View
Brake Master Cylinder Operation, F-150, F-250, F-350
Section 06-06: Brake System, Hydraulic | 1996 F-150, F-250, F-350, Bronco and F-Super Duty Workshop Manual |
The brake master cylinder (2140) is a dual-piston type. When the brake pedal (2455) is depressed, pressure is applied by mechanical linkage to the primary and secondary pistons in the brake master cylinder. The brake master cylinder pistons in turn apply hydraulic pressure to the front and rear brake systems.
Brake Master Cylinder, Cutaway View
Brake Master Cylinder Operation, F-150, F-250, F-350
| Item | Part Number | Description |
|---|---|---|
| 1 | 2005 | Power Brake Booster |
| 2 | 2140 | Brake Master Cylinder |
| 3 | 2B120 | Disc Brake Caliper |
| 4 | 2B373 | Anti-Lock Brake Control Module |
| 5 | 2200 | Rear Brake Shoe and Lining |
| 6 | 2455 | Brake Pedal |
On all vehicles except F-Super Duty, the brake master cylinder is assisted by a power brake booster (2005). On F-Super Duty, a Bendix Hydro-Boost is used. Information about the vacuum booster is in Section 06-07A. Information on the Bendix Hydro-Boost is in Section 06-07C.
Brake Master Cylinder Operation, F-Super Duty Chassis Cab
| Item | Part Number | Description |
|---|---|---|
| 1 | 2455 | Brake Pedal |
| 2 | 2005 | Power Brake Booster |
| 3 | 2140 | Brake Master Cylinder |
| 4 | 2B120 | Disc Brake Caliper |
| 5 | 2B547 | Brake Load Sensor Proportioning Valve |
| 6 | 1102 | Disc Brake Hub and Rotor, Rear |
Brakes, Rear
The rear drum brake system includes:
The rear drum brakes are a standard system with rear wheel cylinders mounted at the top of the rear brake backing plates.
The rear brake system is a more complex system. Trucks are designed to carry a wider range of loads under more severe driving conditions than passenger cars. As explained earlier, the heavier the load in the rear, the more braking force can be applied.
It is also true that trucks often run with light or no loads. Whatever the loading, truck rear brakes have to provide sufficient braking force without causing the rear wheels to lock up prematurely.
The rear disc brake system includes:
The disc brake is of the rail slider caliper design, with two caliper pistons on the same side of the disc brake rotor. The unit consists of a rear disc brake caliper which slides on two rails.
The caliper contains the two caliper pistons. The caliper pistons and caliper bores are protected by boot seals fitted to a groove in the caliper piston and a groove in the rear disc brake caliper housing.
Brakes, Front
The front disc caliper used on F-150 and Bronco vehicles is a dual pin sliding disc brake caliper, single piston type. The system has a dual brake master cylinder and front disc brake hub and rotor.
Four-wheel ABS is standard on Bronco. The ABS wheel end includes an ABS sensor mounted to the knuckle and a tone ring pressed onto the rotor. Refer to Section 06-09A or Section 06-09B for servicing the ABS system.
The front disc caliper used on F-250 and F-350 vehicles is a dual pin sliding disc brake caliper, dual piston type. The system has a dual brake master cylinder and front disc brake hub and rotor.
The front disc caliper used on F-Super Duty series vehicles is a rail slider disc brake caliper, dual piston type. The system uses a dual brake master cylinder and a Hydro-Boost brake boost.
Dual Hydraulic Brake System
To protect against total brake failure caused by worn or damaged parts, the dual hydraulic brake system is split into front and rear subsystems. The front brakes are served by one brake master cylinder piston and outlet port and the rear brakes are served by the other brake master cylinder piston and outlet port.