Master Cylinder Rebuild Kits

Master Cylinder Rebuild Kits: bring back a spongy brake instead of buying a whole new unit

The master cylinder is what turns lever or pedal pressure into hydraulic pressure at your calipers. When the seals inside it wear or swell, you get a lever that creeps to the bar, a pedal that sinks, or fluid seeping past the piston. Master cylinder rebuild kits give you the internals - pistons, cups, seals and small parts - to restore that bore instead of replacing the entire casting. If the body is sound and clean, a rebuild is the faster, cheaper fix, and it's a job most home mechanics can do on the bench.

What we stock

There are 24 rebuild kits on this page, from 4 brands. Bikers Choice makes up the bulk with 16 kits, All Balls Racing covers 6, and Performance Machine and Wilwood each bring one. Current in-stock pricing runs from $24 to $100 - a range, not a promise. Coverage leans toward powersports: Harley-Davidson XL, FLT, FX, FL, FXR, FLH and Big Twin, plus Arctic Cat 400 DVX, Kawasaki KFX250 Mojave, Honda CBR600RA ABS and TRX250X, and Can-Am Outlander 330. Fitment data is listed on 18 of these kits, spanning model years 1972 through 2024.

How to choose

Rebuild kits are bore- and model-specific, so the two things that matter are the exact fitment and the piston bore diameter. A Harley touring kit like the Bikers Choice 5/8 rear kit is cut for a 5/8-inch bore and won't serve a different diameter. If you run aftermarket controls, match the kit to the cylinder brand - the Performance Machine 9/16 Contour kit and the Wilwood GS kit for .625in bore are built for their own cylinders. For a stock ATV or dirt-bike master cylinder, All Balls kits like the Kawasaki KFX250 Mojave rear kit are cut to the OE part. If the bore is scored or corroded past cleanup, a kit won't save it - go to a complete master cylinder instead.

What else you need with it

Plan a rebuild as part of a full hydraulic refresh. If the calipers are also tired, pair this with caliper rebuild kits. Fresh brake lines firm up feel once the cylinder is sorted, and worn brake pads or scored brake rotors are worth checking while the system is apart. A damaged brake lever is a common companion job. Browse everything in Brakes to line up the rest of the parts.

Fitment help and ordering

Not sure a kit matches your bore or year? Call fitment help at 813-535-5801 before you order, or reach us through contact us. All orders ship free, and Affirm and Katapult financing is available at checkout.

Master Cylinder Rebuild Kits: bring back a spongy brake instead of buying a whole new unit

The master cylinder is what turns lever or pedal pressure into hydraulic pressure at your calipers. When the seals inside it wear or swell, you get a lever that creeps to the bar, a pedal that sinks, or fluid seeping past the piston. Master cylinder rebuild kits give you the internals - pistons, cups, seals and small parts - to restore that bore instead of replacing the entire casting. If the body is sound and clean, a rebuild is the faster, cheaper fix, and it's a job most home mechanics can do on the bench.

What we stock

There are 24 rebuild kits on this page, from 4 brands. Bikers Choice makes up the bulk with 16 kits, All Balls Racing covers 6, and Performance Machine and Wilwood each bring one. Current in-stock pricing runs from $24 to $100 - a range, not a promise. Coverage leans toward powersports: Harley-Davidson XL, FLT, FX, FL, FXR, FLH and Big Twin, plus Arctic Cat 400 DVX, Kawasaki KFX250 Mojave, Honda CBR600RA ABS and TRX250X, and Can-Am Outlander 330. Fitment data is listed on 18 of these kits, spanning model years 1972 through 2024.

How to choose

Rebuild kits are bore- and model-specific, so the two things that matter are the exact fitment and the piston bore diameter. A Harley touring kit like the Bikers Choice 5/8 rear kit is cut for a 5/8-inch bore and won't serve a different diameter. If you run aftermarket controls, match the kit to the cylinder brand - the Performance Machine 9/16 Contour kit and the Wilwood GS kit for .625in bore are built for their own cylinders. For a stock ATV or dirt-bike master cylinder, All Balls kits like the Kawasaki KFX250 Mojave rear kit are cut to the OE part. If the bore is scored or corroded past cleanup, a kit won't save it - go to a complete master cylinder instead.

What else you need with it

Plan a rebuild as part of a full hydraulic refresh. If the calipers are also tired, pair this with caliper rebuild kits. Fresh brake lines firm up feel once the cylinder is sorted, and worn brake pads or scored brake rotors are worth checking while the system is apart. A damaged brake lever is a common companion job. Browse everything in Brakes to line up the rest of the parts.

Fitment help and ordering

Not sure a kit matches your bore or year? Call fitment help at 813-535-5801 before you order, or reach us through contact us. All orders ship free, and Affirm and Katapult financing is available at checkout.