Rebuild Kits & Parts
About Rebuild Kits & Parts
A rebuild kit replaces the rubber seals and small wear parts inside a caliper or master cylinder, so the unit can be used again instead of replaced. Riders turn to one when a caliper drags, a lever leaks fluid, a piston is sticking, or the brake feels soft after the lines and pads check out.
First pick the right unit. Titles separate caliper rebuild kits from master cylinder rebuild kits, and many also say front or rear. Kits are listed by make, model and year range, such as the GSX-R and CBR models here, and some cover a long list of models, so read the fit carefully. Bolt kits for rotor fasteners are also listed. A kit helps only if the bore and pistons are in good shape, so if they are pitted or corroded, replace the unit. A rebuild also needs fresh fluid and a bleed.
Brands in this category include HardDrive, Drag Specialties, Parts Unlimited, Brembo and Prox. You will be working on Brake Calipers & Brackets or Brake Master Cylinders, and it is worth checking Brake Pads and Brake Lines, Hoses & Fittings at the same time. The whole group is Brakes & Brake Parts.
FAQs on brake rebuild kits
What is in a brake caliper rebuild kit?
Kits generally include seals for the pistons and dust seals, and some add pistons, bleeder screws or pins. The contents vary by kit, so read the description to see what your listing includes.
Should I rebuild a caliper or replace it?
If the piston bores and pistons are clean and undamaged, a seal kit is often enough. If the bore is pitted, the pistons are corroded, or the body is cracked, replace the caliper.
Can a master cylinder rebuild fix a spongy lever?
It can if worn or leaking seals are the cause. A spongy lever can also come from air in the lines, old fluid or a worn hose, so inspect the system and bleed it after the rebuild.
What can I clean caliper parts with during a rebuild?
Use brake cleaner or clean brake fluid. Do not use petroleum-based solvents, oil or grease, because they swell rubber seals and ruin them. Keep dirt out and reassemble with the lubricant the kit calls for.
How do I match a rebuild kit to my brake?
Check the model, year and whether it is front or rear, and whether the kit is for a caliper or a master cylinder. Compare the markings or part number on your caliper with the listing, or use the Ride Finder at the top of the page.
