Brake Proportioning/Combination Valve: Description and Operation

This system uses proportioning valves to balance front to rear braking by controlling, at a given ratio, the increase in rear brake system hydraulic pressure above a preset level. Under light pedal application, the proportioning valves allow full hydraulic pressure to be applied to the rear brakes.

Fig 35 Type 3 Proportioning Valve Identification:

There are two proportioning valve assemblies used in each vehicle. Due to differences in thread size, each valve has a different part number. During any service procedures, identify valve assemblies by part number or color code.