Wilwood High-Volume Tandem Master Cylinder, 15/16-inch Bore, Bare Aluminum with Pushrod

A fifteen-sixteenths-inch bore and threaded pushrod make this bare aluminum tandem master a manual-brake option for a properly matched custom system. Separate reservoir chambers feed two hydraulic circuits, with outlet choices on either side of the housing. Established in 1977 by Bill Wood, Wilwood Engineering designs and manufactures disc brake systems from its base in Camarillo, California. Calipers, fittings, rotors, valves, master cylinders and brake lines serve its motorsport, street-performance and specialized applications. The full assembly, including its mating connections and operating requirements, governs the correct part selection.

Technical Details

• Manufacturer part number: 260-13375
• Material: Aluminum
• Cylinder bore: 15/16"
• 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: Bare
• 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

Match the 3.22–3.40-inch mounting span, pedal ratio and fluid demand rather than assuming a direct vehicle replacement. Allow the full 1.10-inch stroke before the pedal reaches any stop, and let the piston return completely. The supplied adapters suit double-flared lines; a proportioning valve and vehicle-specific linkage are separate system choices.

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.