Wilwood Chrome Powder-Coated Manual Tandem Master Cylinder, 7/8-inch Bore and Pushrod

A chrome powder-coated body and included threaded pushrod distinguish this 7/8-inch manual-brake master. Its integral fluid supply avoids separate reservoir mounting, while the tandem piston arrangement keeps the two hydraulic circuits independent. Wilwood Engineering began in 1977 under founder Bill Wood and is based in Camarillo, California. The company designs and builds disc brake systems for motorsport, street-performance and specialized applications, with a range extending through calipers, rotors, valves, brake lines, fittings and master cylinders. Individual parts must be compatible with the system in which they operate.

Technical Details

• Manufacturer part number: 260-9439-P
• Material: Aluminum
• Cylinder bore: 7/8"
• Pressure circuits: 2
• Stroke Length: 1.10 in
• Reservoir Type: Integral
• Fluid capacity: 8.0 / 4.8 oz
• Flange-to-end length: 8.15"
• Overall Length: 12.26"
• Mounting centers: 3.22–3.40"
• Pushrod dimensions: 4.11" x 3/8-24
• Finish: Chrome powder 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

Fitment & Compatibility

Use the actual caliper displacement and pedal geometry to select the bore. Check 3.22–3.40-inch flange centers, 3/8-24 linkage engagement and room for the reservoir lid; this general pushrod is not the dedicated Mustang eyelet assembly.

Manufacturer Documents

• Wilwood product specifications
• Wilwood DS487 instructions and specifications
• Wilwood FL162 instructions and specifications

With more than 20 years of experience, PMB Performance can help compare the specified part with the assembly you are servicing. Include the existing part identification and relevant hydraulic dimensions.