Hydraulic Component Descriptions

PRESSURE MODULATOR VALVE (PMV) ASSEMBLY
The PMV assembly consists of three components: a pump and motor assembly, a valve body, and a brake fluid reservoir. The reservoir is the only serviceable component.

The brake fluid reservoir supplies the pump motor assembly with brake fluid; the pump motor assembly maintains brake pedal height; and the valve block controls fluid pressure to each individual wheel.

When equipped with traction control, the PMV assembly also houses the isolation valves. During traction control mode, these valves isolate the front brake hydraulic circuits from the master cylinder and rear brake hydraulic circuits. This allows pressure to be delivered only to the front drive wheels.


PROPORTIONER VALVES
In the rear brake circuits are two proportioner valves which limit brake pressure buildup at the rear wheels. Since the front brakes do the majority of the braking work, less pressure is required for the rear brakes under certain conditions. The proportioner valve improves front to rear brake balancing during normal braking.