7/8" Bore Master Cylinder, 3/8-24" Ports Each Side, MC1322H-7/8, w/ Adjustable Proportioning Valve Kit (Drum/Drum)

7/8" Bore Master Cylinder & Adjustable Proportioning Valve Kit w/ (2) 10lb Residual Check Valves – Manual Drum/Drum

Everything you need for a strong, balanced manual drum brake system in one box.

Building a car or truck without a booster? Getting a manual drum brake system right takes three things: the right bore size, adjustable brake balance and residual pressure to keep the pedal firm. This combo gives you all three. It pairs our best-selling 7/8" bore universal Corvette style master cylinder with a complete adjustable proportioning valve kit and two 10lb residual check valves, so you can stop guessing and start driving. 

7/8" bore: made for manual brakes

Without a power booster, your leg does all the work, so bore size matters. The smaller 7/8" bore builds more line pressure from the same pedal effort than a 1" or larger bore. That means firm, confident stops without fighting the pedal. It’s the go-to choice for non-power brake setups on hot rods, street rods, muscle cars and classic trucks.

Classic Corvette style, universal fit
The master cylinder has the timeless Corvette style body and a bail-wire reservoir cover. Its universal design fits a wide range of builds, and 3/8"-24 outlet ports on each side let you plumb left or right, whichever suits your engine bay.

Dial in your brake balance
The adjustable proportioning valve has a big, easy-grip knob clearly marked INCREASE and DECREASE. Turn it to set rear brake pressure until the car stops straight and level, with no rear lockup and no nose-diving. Every build is different, and this lets you tune yours in seconds.

10lb residual check valves for a firm pedal
Drum brake return springs pull the shoes away from the drum. Without residual pressure, fluid drains back and the wheel cylinder cups can lose their seal, which leaves you with a low, spongy pedal. The two red anodized 10lb residual check valves hold just enough pressure in the lines to keep the cups seated and the shoes ready, without causing drag.

Brake lights built in
The proportioning valve has a built-in brake light pressure switch. The 2-wire pigtail and connector boot are included, so wiring your brake lights is simple and clean.

Why buy the combo?

• Parts that are matched to work together, with no guessing at compatibility
• One order and one box instead of hunting down parts from different sellers
• Save compared to buying each piece separately

What’s included

• (1) 7/8" bore universal Corvette style master cylinder (MC1322H-7/8) with 3/8"-24 ports on each side
• (1) Adjustable knob-style proportioning valve with built-in brake light pressure switch
• (2) Red anodized 10lb residual check valves with brass fittings
• (5) 3/8"-24 steel tube nuts
• (1) 2-wire brake light pigtail
• (1) Connector boot

Features

• 7/8" bore for higher line pressure in manual (non-power) brake systems
• Universal Corvette style body with bail-wire cover
• 3/8"-24 outlet ports on each side for left- or right-hand plumbing
• Knob-adjustable rear brake proportioning
• (2) 10lb residual check valves for drum brakes
• Built-in brake light pressure switch with pigtail
• Great for hot rods, street rods, muscle cars and classic trucks

Please note: This kit is made for manual drum/drum brake systems. 10lb residual valves should not be used on disc brakes, because they can cause the pads to drag. For disc/drum or disc/disc systems, see our other master cylinder and proportioning valve kits. Brake lines, pushrod and mounting hardware are not included. Check your mounting and pushrod fit before installing.