Brake Caliper Rebuild Kits

Is brake fluid seeping out at the caliper, or is a piston sticking so the pad drags against the disc? With a rebuild kit you can replace the seals and, in some kits, the pistons too, so you can reuse your existing caliper.

What a rebuild kit replaces

The seals in a brake caliper hold the brake fluid in and pull the piston back slightly when you release the brake. Over time they can harden or start leaking, and dirt and corrosion can make the piston move sluggishly. This can cause leaks, uneven wear on the brake pads or a dragging brake. Some kits contain only seals, while others also include new pistons.

How to choose the right kit

The kit must match your specific caliper, so check these points:

• Whether it is for the front or rear caliper
• Number of pistons and caliper make – e.g. there are kits for 4-piston calipers that do not fit Brembo
• Model and year range, e.g. Polaris Ranger and RZR or Big Twin and Sportster
• The original part number, which some kits state they replace

We carry kits from brands such as QuadBoss, Bikers Choice, OMIX, Baer Brakes and Alcon.

Fitting and follow-up checks

Inspect the cylinder bore before you rebuild. If it is corroded or scored, new seals typically cannot solve the problem, and a new brake caliper is often the better choice. Clean the parts thoroughly, use the brake fluid or assembly lubricant specified by the manufacturer, and bleed the system afterwards. Test the brake carefully before driving normally again.

Frequently asked questions

When should the caliper be rebuilt rather than replaced?

If the bore and piston are free of corrosion and scoring, new seals can typically fix leaks and sticking pistons. If the bore is damaged or the caliper is cracked, a new caliper is usually necessary.

What is the difference between a seal kit and a kit with pistons?

A seal kit contains only the seals. A kit with pistons also gives you new pistons, which can be relevant if the old ones are rusty, scored or stuck. See the product description for the exact contents.

Do the brakes need bleeding after a rebuild?

Yes. Once the caliper has been taken apart, air gets into the system, which can cause a soft pedal or lever. Bleed according to the manufacturer's instructions and check for leaks before you ride or drive.