Section 06-06: Brake System, Hydraulic
1996 F-150, F-250, F-350, Bronco and F-Super Duty Workshop Manual
DESCRIPTION AND OPERATION

Fluid Control Valve, Brake Master Cylinder

The brake master cylinder fluid control valve (2C161) regulates the hydraulic pressure in the rear brake system. It is located on the brake master cylinder (2140) and is screwed into the rearmost outlet port. When the brake pedal (2455) is applied, the full brake fluid pressure passes through the brake master cylinder fluid control valve to the rear brake system until the valve's split point is reached. Above its split point, the brake master cylinder fluid control valve begins to reduce the hydraulic pressure to the rear brakes, creating a balanced braking condition between the front and rear wheels (1007) to minimize rear wheel lockup during hard braking.

In case of the front brake system malfunction, the brake master cylinder fluid control valve has a bypass feature which allows full hydraulic pressure to the rear brake system.