Wilwood High Volume Tandem Master Cylinder, 1 In w/Adj Prop Block

Master Cylinder

Wilwood's Tandem Aluminum Master Cylinder is available in 1 inch bore size and a black e-coat. 7/8" & 15/16" bore master cylinders are designed primarily for manual applications and include a pushrod. The 1" bore can be used in manual and power assisted applications and does not come with a pushrod. The 1.125" bore is designed for use primarily with power brake applications, either from vacuum assist or hydraulic assist systems. They're designed for mount flanges from 3.22" to 3.40" , common measurements for most domestic cars and trucks from the mid 1960s to present, and offer fluid outlet ports on both sides of the bore. The stroke is set at 1.10" with a volume ratio of 2:1 between the primary and secondary chambers. Machined from high-pressure die castings, each master cylinder weighs only 3lbs, a 75% weight savings over most cast iron OE type master cylinders. We also offer a our combination proportioning valve kit, which includes brackets and stainless lines specifically for use with these master cylinders, see PN 260-13190, or 220-13189 for retrofit kit.

Proportioning Valve

This adjustable proportioning block allows you to run lines from the master cylinder to the block and then to the appropriate wheels. What is neat about it is that it also contains the proportioning valve and brake light switch. This dramatically reduces the amount of fittings needed and potential leaks.

The adjustable proportioning valve regulates rear brake pressure, helping to maintain correct brake bias between front and rear brakes. It is designed for dual bowl master cylinders. The distribution block connects to the master cylinder and distributes brake fluid to all four wheels. An easy to turn handle with directional arrows makes it simple to either increase or decrease rear brake pressure.

The block accepts 3/16" brake lines and the inlets and outlets on this unit are 3/8"-24 inverted flare females.  It has two inlets from the master cylinder, two outlets to the front brakes and one outlet to the rear brakes.  It includes five stainless steel 3/16" fittings and wiring pigtail for rear brake light switch. Mounts to any convenient location. This is not a direct factory replacement for original blocks. Some line modifications may be necessary.

Learn more about how adjustable proportioning valves work by reading our tech article. Brake System Selection.  

Installation Instructions (PDF)

 910-31358 Instructions (PDF)