Wilwood Mustang Manual-Brake Master and Left Valve Kit, Black 15/16-Inch Compact Tandem

A black 15/16-inch compact tandem master provides the selected bore in this Mustang manual-brake kit. The supplied pushrod connects the pedal, and formed tubes join the master to the left-mounted valve. The disc brake systems Wilwood Engineering designs and manufactures include calipers, rotors, master cylinders, brake lines, valves and fittings. The company dates to Bill Wood's founding in 1977 and is based in Camarillo, California. Motorsport, specialized and street-performance applications all call for parts matched to the operating requirements of the full system.

Technical Details

• Manufacturer part number: 261-15523-BK
• Material: Aluminum
• Cylinder bore: 15/16"
• 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

Compare the classic Mustang clevis and flange with the documented installation. Confirm bore choice, pedal travel and brake-circuit routing.

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 offers over 20 years of parts and brake-fitment experience. For a compatibility check, provide the existing assembly and the dimensions that govern the replacement.