Wilwood 260-8556-BK High-Volume Tandem Master Cylinder 1 1/8" Bore

Vehicle Fitment

• Universal fit - for custom, performance, and power-brake equipped vehicles with compatible master cylinder flange dimensions
• Designed to mount to 3.22"-3.40" master cylinder flanges common on many domestic cars and trucks (1960s-present)

Features

• High-volume tandem aluminum master cylinder with 1 1/8" bore for strong hydraulic capacity
• Integral aluminum reservoir with sealed cap for reliable fluid containment
• Dual outlet ports (both sides) for flexible brake line routing
• Black E-coat finish for corrosion resistance and a polished look
• Machined from high-pressure die castings for strength with weight savings
• 1.10" piston stroke with a 2:1 volume ratio between primary and secondary chambers
• Weighs approximately 3 lbs - ~75 % lighter than many OE cast iron units
• Designed for power brake applications (vacuum or hydraulic assist) and heavy-duty systems

Specifications

• Part Number: 260-8556-BK (Wilwood High-Volume Tandem Master Cylinder)
• Bore Size: 1.125" (1 1/8")
• Reservoir: Integral aluminum (14.4 cu in primary / 8.7 cu in secondary approx.)
• Piston Stroke: 1.10"
• Outlet Ports: Dual - 3/8-24 IF or 1/2-20 IF / 3/8-24 IF or 9/16-18 IF
• Mount Flange Fit Range: 3.22" - 3.40"
• Material: High-pressure die-cast aluminum
• Finish: Black E-coat

Included Components

• 1x Wilwood high-volume tandem master cylinder (260-8556-BK)

Product Description

The Wilwood 260-8556-BK is a high-volume tandem chamber master cylinder engineered for performance brake systems and power-assisted brake applications. With a 1 1/8" bore and integral reservoir, this master cylinder delivers increased fluid volume and hydraulic capacity compared to smaller units, helping ensure strong and consistent brake pedal performance under demanding driving conditions. Its die-cast aluminum construction provides significant weight savings over traditional cast iron cylinders while maintaining structural strength and heat resistance.

Featuring dual fluid outlets on both sides of the bore, the 260-8556-BK allows flexible brake line routing in custom and retrofit applications. The design fits common firewall master cylinder flange sizes from approximately 3.22" to 3.40", making it suitable for a wide range of domestic cars and trucks from the mid-1960s through modern builds that use power brake systems. The integral reservoir and 2:1 volume ratio between chambers provide ample fluid capacity for improved brake response and balance in performance street setups, restorations, and heavy vehicles equipped with vacuum or hydraulic assist.