Jeep CJ 1945-1970 Repair Information

Proportioning Valve


See Figures 1 and 2

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Fig. Fig. 1: View of a Type D combination valve used on some Jeep models

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Fig. Fig. 2: Identification of the inlet and outlet ports of a Type W combination valve used on some Jeep models

Some later Jeep models may be equipped with a proportioning valve, which is a three part unit containing a metering valve, pressure differential valve and brake pressure warning switch. If any of these functions fails, the unit must be replaced. It is not repairable.

The valve is located on the frame rail, directly under the driver's position, if equipped.

Brake linings may contain asbestos. Asbestos is a known cancer-causing agent. When working on brakes, remember that the dust which accumulates on the brake parts and/or in the drum contains asbestos. Always wear a protective face covering, such as a painter's mask, when working on the brakes. NEVER blow the dust from the brakes or drum! There are solvents made for the purpose of cleaning brake parts. Use them!

Clean, high quality brake fluid is essential to the safe and proper operation of the brake system. You should always buy the highest quality brake fluid that is available. If the brake fluid becomes contaminated, drain and flush the system, then refill the master cylinder with new fluid. Never reuse any brake fluid. Any brake fluid that is removed from the system should be discarded.


  1. Disconnect the brake lines at the valve and plug them.
  3. Unbolt and remove the valve.
  5. Installation is the reverse of removal. Bleed the system.