Wilwood Black Compact Master Cylinder Kit for Mustang Manual Brakes, 7/8-Inch Bore, Left Valve

The compact 7/8-inch tandem master is supplied with the Mustang manual-brake pushrod and left-mounted combination valve. Its integral reservoir layout keeps the complete master package at the firewall. Camarillo, California is home to Wilwood Engineering, founded in 1977 by Bill Wood. Its disc brake design and manufacturing range includes valves, master cylinders, calipers, brake lines, rotors and fittings for street-performance, specialized and motorsport use. These parts are selected together so the completed braking system has the required hydraulic and mechanical arrangement.

Technical Details

• Manufacturer part number: 261-15522-BK
• Material: Aluminum
• Cylinder bore: 7/8"
• Pressure circuits: 2
• Stroke Length: 1.10 in
• Reservoir Type: Integral tandem chambers, 7.8 and 4.7 oz
• Fluid capacity: 7.8 / 4.7 oz
• Flange-to-end length: 6.55"
• Overall Length: 12.32"
• Mounting centers: 3.22–3.40"
• Pushrod dimensions: 5.75"
• Finish: Black E-coat
• Native pressure ports: 1/2-20 at both circuits; use the correct included outlet adapters and seal washers
• Circuit outlet adapters: Primary: 3/8-24 or 1/2-20 inverted flare; secondary: 3/8-24 or 9/16-18 inverted flare
• Hydraulic relationship: Equal pressure output from the two circuits before external proportioning; 2:1 primary/secondary volume relationship
• Service: Factory rebuild only; do not disassemble the tandem piston assembly
• Kit contents: Master cylinder, left-side combination proportioning valve and bracket, formed stainless connecting tubes and mounting hardware
• Combination-valve functions: Adjustable rear pressure, isolated front/rear circuits, front-line junction and hydraulic brake-light switch

Fitment & Compatibility

Confirm the specified classic Mustang pedal and mounting arrangement. Match the clevis, master bore and remaining brake-system requirements.

Wilwood’s kit summary gives a 1964–1973 Ford/Mustang range, while the corresponding bare-master family identifies 1964–1972. Confirm the actual manual pedal, supplied eyelet and mounting geometry, particularly for 1973, before ordering.

Manufacturer Documents

• Wilwood product specifications
• Wilwood FL162 instructions and specifications
• Wilwood DS1287 instructions and specifications
• Wilwood DS1178 instructions and specifications
• Wilwood FL311 instructions and specifications

PMB Performance has more than 20 years of experience matching brake components. Share the actual mounting, linkage and hydraulic arrangement when requesting fitment assistance.