Master cylinder features:
The included valve is also called a combination valve, as it performs all of the necessary valving functions with a disc brake conversion. These functions include the following:
As more force is applied to the brakes and the car begins to lean forward, less braking force is needed in the rear. This valve decreases the pressure to the rear, preventing lock up.
Metering is used in the front disk brake portion in the disc/drum system to delay application of the front discs allowing the slower reacting drum brakes to catch up. This provides rear stability on wet surfaces and helps prevent front pad wear. There is no metering function with the disc/disc setup.
Drum Brakes require residual pressure of 10 lbs. to be held in the line. This pressure keeps the brake shoes close to the drums giving you a more firm pedal feel. The disc/disc setup does not require this pressure.
This valve has a system failure switch that will alert you when half of your braking system is not working properly.