Master Cylinders

Master Cylinders: The Part That Turns Pedal Pressure Into Stopping Force

The master cylinder is where your foot or hand lever becomes hydraulic force. Push the pedal, the pushrod moves the piston inside the bore, and brake fluid gets forced down the lines to the calipers or wheel cylinders. Bore size is the whole story here: it decides how much fluid you move and how much pedal effort you feel. Fit the wrong bore for your caliper setup and you get either a mushy, long-travel pedal or a brick you can barely modulate. Most people fitting one of these master cylinders are either replacing a worn, leaking unit or matching a fresh cylinder to a brake upgrade.

What We Stock

There are 117 master cylinders in this category right now, spanning 13 brands. Wilwood leads with 73 units, followed by Bikers Choice at 12, Wehrli at 7, Radium Engineering at 6 and Performance Machine at 4, with GrimmSpeed, Perrin Performance, Kuryakyn, Torque Solution, BLOX Racing, TwinPower, ISR Performance and Exedy filling out the rest. Prices currently run from $24 to $531 for what's in stock, so this is not a promise but the live range. Coverage leans two ways: Harley-Davidson motorcycle applications (XL, FL, Big Twin, Dyna, Touring) and sport and truck platforms including the Nissan Skyline and Frontier, Subaru WRX and Impreza, Toyota GR Supra and GR Corolla, Acura Integra, Ford Mustang and Chevrolet Duramax. Fitment data is listed on 36 products, with a year range from 1958 to 2024.

How to Choose

Start with bore size and application. For a car, a tandem cylinder like the Wilwood 15/16in tandem for Mustang with bracket and valve gives you a complete pushrod-and-valve package rather than a bare casting, and the Wilwood Mopar compact tandem kit with combination valve works the same way for that platform. For a Harley, decide front versus rear and match your handlebar: the Performance Machine 11/16 front Contour M/Cyl is a finished, styled front unit, while the Performance Machine 11/16 rear M/Cyl in chrome covers 00-07 FLH/FLT. If you want a direct replacement assembly, the Bikers Choice chrome Dyna assembly replaces a specific H-D part number, and the Bikers Choice 9/16 bore chopped-handlebar cylinder suits FL, ST Dyna and XL. The trade-off is simple: complete kits cost more but take the guesswork out; bare assemblies cost less if you already have the valve and lines.

What Else You Need

A master cylinder rarely goes in alone. Fresh brake lines keep the hydraulic side clean, and if you're upgrading the whole corner look at brake calipers, brake pads and brake rotors to match. Riders replacing a hand-lever cylinder often need new brake levers, and rebuilders should check caliper rebuild kits too. Browse the full Brakes section to see how the categories tie together.

Fitment Help and Ordering

Not sure which bore or application fits your build? Call for fitment help at 813-535-5801 or reach us through contact us. Every order ships free, and Affirm and Katapult financing is available.

Master Cylinders: The Part That Turns Pedal Pressure Into Stopping Force

The master cylinder is where your foot or hand lever becomes hydraulic force. Push the pedal, the pushrod moves the piston inside the bore, and brake fluid gets forced down the lines to the calipers or wheel cylinders. Bore size is the whole story here: it decides how much fluid you move and how much pedal effort you feel. Fit the wrong bore for your caliper setup and you get either a mushy, long-travel pedal or a brick you can barely modulate. Most people fitting one of these master cylinders are either replacing a worn, leaking unit or matching a fresh cylinder to a brake upgrade.

What We Stock

There are 117 master cylinders in this category right now, spanning 13 brands. Wilwood leads with 73 units, followed by Bikers Choice at 12, Wehrli at 7, Radium Engineering at 6 and Performance Machine at 4, with GrimmSpeed, Perrin Performance, Kuryakyn, Torque Solution, BLOX Racing, TwinPower, ISR Performance and Exedy filling out the rest. Prices currently run from $24 to $531 for what's in stock, so this is not a promise but the live range. Coverage leans two ways: Harley-Davidson motorcycle applications (XL, FL, Big Twin, Dyna, Touring) and sport and truck platforms including the Nissan Skyline and Frontier, Subaru WRX and Impreza, Toyota GR Supra and GR Corolla, Acura Integra, Ford Mustang and Chevrolet Duramax. Fitment data is listed on 36 products, with a year range from 1958 to 2024.

How to Choose

Start with bore size and application. For a car, a tandem cylinder like the Wilwood 15/16in tandem for Mustang with bracket and valve gives you a complete pushrod-and-valve package rather than a bare casting, and the Wilwood Mopar compact tandem kit with combination valve works the same way for that platform. For a Harley, decide front versus rear and match your handlebar: the Performance Machine 11/16 front Contour M/Cyl is a finished, styled front unit, while the Performance Machine 11/16 rear M/Cyl in chrome covers 00-07 FLH/FLT. If you want a direct replacement assembly, the Bikers Choice chrome Dyna assembly replaces a specific H-D part number, and the Bikers Choice 9/16 bore chopped-handlebar cylinder suits FL, ST Dyna and XL. The trade-off is simple: complete kits cost more but take the guesswork out; bare assemblies cost less if you already have the valve and lines.

What Else You Need

A master cylinder rarely goes in alone. Fresh brake lines keep the hydraulic side clean, and if you're upgrading the whole corner look at brake calipers, brake pads and brake rotors to match. Riders replacing a hand-lever cylinder often need new brake levers, and rebuilders should check caliper rebuild kits too. Browse the full Brakes section to see how the categories tie together.

Fitment Help and Ordering

Not sure which bore or application fits your build? Call for fitment help at 813-535-5801 or reach us through contact us. Every order ships free, and Affirm and Katapult financing is available.