Wagoneer L6-258 4.2L VIN C 2-bbl (1982)
Brake Proportioning/Combination Valve: Description and Operation
Fig. 1 Type ``D'' combination valve. Exc. 1984-87 Cherokee & Wagoneer, 1984-86 CJ & Scrambler, 1986-87 Commanche & 1987 Wrangler
Fig. 2 Type ``W'' combination valve. 1984-87 Cherokee & Wagoneer, 1984-86 CJ & Scrambler, 1986-87 Commanche & 1987 Wrangler
EXC. 1984-87 CHEROKEE & WAGONEER, 1984-86 CJ & SCRAMBLER, 1986-87 COMANCHE & 1987 WRANGLER
These vehicles use a three function combination valve, consisting of a one piece housing containing a front brake metering valve, a pressure
differential warning valve, and a rear brake proportioning valve. This valve also serves as the junction block for the front brakes.
Some models use a type "D" valve, while other models use a type "W" valve. The two valves differ in external appearance and internal component
design, but their function and operation are identical.
The front brake metering valve assists in providing balanced front to rear braking by delaying full hydraulic fluid pressure to the front disc brakes until
the rear drum brakes overcome return spring tension and the linings contact the drums. When the brakes are not applied, the metering valve allows
free flow of brake fluid.
The pressure differential warning valve activates the brake warning lamp whenever there is a pressure loss in either the front or rear brake system.
When there is a pressure loss in either system, normal pressure from the other system moves the valve piston, which completes the electrical circuit
between the switch and the brake warning lamp.
The rear brake proportioning valve provides balanced front to rear braking action during high pedal pressure stops.
