Dodge Durango
 Service Manual
Brakes » Base brake system » Description and operation
Combination valve

The combination valve contains a pressure differential valve and switch and a proportioning valve.

The combination valve/proportioning valve are not repairable and must be replaced as an assembly.


The pressure differential switch is connected to the brake warning lamp. The switch is triggered by movement of the switch valve. The purpose of the switch is to monitor fluid pressure in the separate front/rear brake hydraulic circuits.

A decrease or loss of fluid pressure in either hydraulic circuit will cause the switch valve to shuttle forward or rearward in response to the pressure differential. Movement of the switch valve will push the switch plunger upward. This closes the switch internal contacts completing the electrical circuit to the warning lamp. The switch valve may remain in an actuated position until repair restores system pressures to normal levels.


The proportioning valve is used to balance frontrear brake action at high decelerations. The valve allows normal fluid pressure during moderate braking.

The valve only controls fluid pressure during high decelerations brake stops, when a percentage of rear weight is transferred to the front wheels.

    More about «Description and operation»:

    Brake system

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    Brake pedal

    Stop lamp switch

    Red brake warning lamp

    Power brake booster

    Master cylinder

    Combination valve

    Front disc brakes

    Drum brakes

    Parking brakes

    Brake hoses and lines

    Dodge Durango Service Manual / Brakes / Base brake system / Description and operation / Combination valve

    Dodge Durango Service Manual


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