What Is the Purpose of a Brake Proportioning Valve?

Many components comprise a vehicle's braking system.

A vehicle's braking system is not just made up of the brake discs or drums that are attached to each wheel. Instead, there are several components within the engine compartment, such as the brake proportioning valve, that help a vehicle adjust to various braking conditions.

Identification

The brake proportioning valve is part of a vehicle's overall hydraulic brake system, and is located between the back wheels and the master cylinder. Brake fluid runs throughout the system, keeping it pressurized for when the brake pedal is applied and functioning occurs.

Function

The purpose of the brake proportioning valve is to equalize the braking pressure between the rear and front brakes. If a driver brakes hard, the brake proportioning valve coordinates more pressure to assist the front brakes so that the rear wheels do not freeze or lock.

Features

Some brake proportioning valves are housed in a different valve configuration called a combination valve. This valve is simply a mixture of the brake proportioning valve and the pressure differential valve, which is in control of the brake warning light. This light illuminates if there are possible failures within the braking system.

References

• Family Car Parts: A Short Course on Brakes