Wilwood 261-13270-BK Tandem Master Cylinder Kit w/ Prop Valve for OE Bolt-On

Vehicle Fitment

• Universal bolt-on kit--fits many OE brake mounts (Chrysler, Corvette, GM, Mustang manual or power brakes)

Fitment Notes

• Includes bracket and proportioning valve--no custom fabrication required
• Designed for manual or power brake systems

Features

• Aluminum tandem-chamber master cylinder with black E-coat finish
• 1-1/8" bore, 0.970 in² area; 1.10" stroke for high volume output
• Integral 8 oz primary / 4.8 oz secondary fluid reservoirs
• Slotted flange mounts directly to OE brake booster/spindle
• Includes stainless steel fluid lines and 2-circuit proportioning valve
• Black powder coat bracket and valve for corrosion protection
• Suits high-pressure custom brake systems across multiple platforms

Specifications

• Part Number: 261-13270-BK
• Bore Size: 1.125" (1-1/8")
• Stroke: 1.10"; Area: 0.970 in²
• Reservoirs: 8.0 oz primary / 4.8 oz secondary (integral)
• Finish: Black E-coat (cylinder, bracket, valve)
• Outlets: 2 x (3/8-24 IF or 1/2-20 IF)

Included Components

• 1x 1-1/8" bore aluminum tandem master cylinder (black E-coat)
• 1x Combination proportioning valve (black E-coat)
• 1x Slotted mounting bracket
• Stainless steel fluid tubes and tube nuts
• Mounting hardware and installation instructions

Product Description

The Wilwood 261-13270-BK tandem master cylinder kit is a premium universal upgrade, designed to bolt onto OE brake booster or spindle mounts found on Chrysler, Corvette, GM, and Mustang manual or power brake systems. Finished in rugged black E-coat, the high-capacity 1-1/8" bore cylinder delivers strong braking performance in custom or upgraded setups.

It includes a combination proportioning valve, stainless steel lines, and a slotted mounting bracket, making installation clean and efficient with no fabrication needed. Internal reservoirs and protective coatings ensure reliability and performance in demanding street and track applications.