A brake caliper that’s stuck or hangs up can cause abnormal pad wear, and it can cause the vehicle to pull to one side. Oftentimes, a sticking brake is caused by the piston not retracting fully into the caliper. In some cases, it is possible to rebuild the caliper instead of buying a more expensive new or rebuilt one.

Brake-caliper repair kits generally include all the necessary seals, O-rings and hardware to perform a typical caliper repair. But these kits usually don’t include a piston. If the piston is scored or pitted beyond repair, your customers will have to replace the caliper.
While caliper rebuild kits are an affordable solution that may prolong the life of the braking system, these kits can only repair limited issues that may affect a caliper over its lifetime. If a caliper body made of cast iron or aluminum is cracked or the bore is deeply scored, a rebuild kit is out of the question. And with the price of many rebuilt calipers as low as they are, consumers and shops often choose to replace the entire caliper because it’s much easier than having to take apart the components and replace them.
But if the caliper is in relatively good shape appearance-wise – meaning you don’t notice any outward damage other than perhaps a torn piston boot or seal – then by all means, take it apart and see if a new kit is all that’s needed. If the boot is torn, then you can often pull it back to inspect the outer edge of the piston for pitting or corrosion. With pads that are worn and a torn boot, the piston is pushed out farther, allowing moisture to easily enter, causing rust and pitting.

Caliper rebuild kits typically only contain a dust boot and a square-cut O-ring to seal the piston to the housing and keep fluid from escaping. However, some manufacturers do sell just the piston if the rest of the system is in good enough shape. Keep in mind, your wholesale customers may not buy these kits (unless there’s no other choice) because there’s more labor involved in a rebuild than merely replacing the caliper.
Also, when a customer asks for a caliper rebuild kit, it’s a good idea to recommend replacing the caliper hardware at that time. The caliper hardware will include the clips, bolts and retaining pins that will help return the component to as-new condition.
One more thing you should recommend is brake fluid (and brake cleaner) if they don’t have any. The more add-on items you can think of will increase the daily sales and add up to significant numbers at the end of the month or quarter. You may even consider offering a brake-repair special where you’ll include the ancillary items – such as towels, gloves, brake fluid and brake cleaner – with either a rebuild kit or rebuilt caliper.
Caliper rebuild kits aren’t for everyone – especially DIYers who may not be very proficient with performing brake jobs other than pads and rotors. Make sure your customers understand that a rebuild kit won’t necessarily be enough on its own, and proper inspection is necessary before determining if it’s the right solution or not.