Replace Or Rebuild — What's The Right Option For Your Calipers?

Your car's calipers are the secret sauce that allows your braking system to function. Each wheel will have its own caliper on a typical modern vehicle with four-wheel disc brakes. While caliper designs vary from manufacturer to manufacturer, all calipers are relatively simple parts that use a hydraulic-actuated piston to squeeze your brake pads against the brake discs (or rotors).

The simplest calipers consist of only a housing, a single piston, and some seals. These calipers are known as floating calipers and apply pressure on only one side. More complex designs (known as fixed calipers) use sets of two or more pistons to apply even pressure to both sides, typically resulting in better braking performance.

What Can Go Wrong With Calipers?

Since even advanced fixed calipers are still relatively simple, it might seem surprising that you'd ever need to repair or replace a caliper. While there isn't much that can go wrong with a caliper, a few problems tend to crop up. Since the piston must slide smoothly within its bore, moisture, dust, and debris can cause problems that may affect the operation of your brakes.

In a worst-case scenario, the piston itself may become damaged or rust, preventing it from moving smoothly against the brake pads. This situation often causes the caliper to stick, leaving it in an extended or retracted position. This situation may stop one of your brakes from working or leave the pads on that wheel in constant contact with the rotor.

In many cases, caliper failures can also be due to issues with the braking system. For example, a collapsed brake hose can prevent hydraulic fluid from entering or leaving the caliper. These failures often cause the caliper to stick, making it initially appear as if there's a problem with the caliper itself and not the brake line.

What Should You Do About a Failing Caliper?

If one caliper fails, there's no reason to expect your others to follow. However, you must make one important decision: replace or rebuild. Caliper rebuild kits typically include two seals: the square-cut seal for the piston and the boot seal that fits on the caliper.

A rebuild kit can address problems with a caliper caused by worn or damaged seals, but installing one can be more labor-intensive than replacing the caliper. Additionally, using a rebuild kit may not be possible if the piston is already damaged or rusty. It's usually a good idea to have a professional auto technician examine your affected caliper to determine if a rebuild is a smart plan.

For simple, single-piston floating calipers, rebuilds may not be cost-effective compared to replacement. On the other hand, more expensive dual-piston floating calipers or fixed calipers with two or four pistons can be much costlier to replace. A rebuild may make more sense if your car uses one of these higher-end components.

To learn more about brakes and calipers, reach out to an auto shop near you.