Brake caliper sticking isn't that common, but it is important to have it diagnosed and fixed right away because it affects the safety of your vehicle.
Brake caplier sticking symptoms: Do you find that your vehicle pulls more to one side when braking? Or perhaps the brakes don't seem to release all the way after you let go of the pedal?
If yes, then you may indeed have a stuck brake caliper. Before you take your car or truck down to a repair shop, learn what causes brake calipers to stick and how you can fix them.
The brake caliper bolts also have slides on them that need to stay lubed. They have protective rubber boots on them to keep the lubrication in, but sometimes careless mechanics tear them when they are installing new brake pads.
Besides causing them to dry out and rust, debris may seep in as well... so they no longer slide like they should. In extreme cases this will cause the brakes to stick. Sometimes you can take these bolts out and recondition them, but you may just need new bolts. If new bolts are not available, then the only solution is to buy a new caliper.
Another thing that can sometimes happen is the bolts will sometimes break off. This happens more often when a mechanic over tightens them. It is important to take your car or truck to a repair shop that you can trust.
Sometimes brake caliper sticking is caused by the piston. As you can see in the image above, the piston has a rubber boot around it. This rubber boot protects, seals and lubricates the piston.
This boot is easily torn when retracting the piston back into the caliper while replacing the brake pads. If it gets torn, then rust and other debris can build up inside the caliper and cause the piston to not slide smoothly. This can cause the brake caliper to stick. Sometimes you can find brake caliper rebuild kits, but most of the time the only way to fix this type of problem is to replace the brake caliper assembly.
Sometimes the brake hoses will wear out internally. This can create a small piece of brake hose to break mostly off, but still have a small piece attached to the main part of the hose.
This will make a sort of valve that lets the brake fluid flow in only one way. When you step on the brake pedal, the fluid could flow to the brake pistons and cause the pads to engage and slow the vehicle... but then when you let off the brakes, the fluid would not be able to return to the master cylinder.
This will cause the caliper to stick and make the vehicle pull to that side. This can be a tough problem to diagnose even for a seasoned mechanic.
One way that it can be done is to raise the vehicle up and step on the brakes, then let off and try to turn the wheels. If one of them won't turn, then open the bleeder valve and see if brake fluid shoots out. If it does, then you know that there was a lot of pressure built up in the braking system. This could be caused by a bad brake hose.
The best way to avoid brake caliper sticking problems is to take care of your brakes. If you replace brake pads and top up brake fluid when needed, then you shouldn't run into any problems with your brake caliper.
Depending on how much mileage you clock up, most calipers will last the life of the vehicle or close to it. Sometimes brake caliper sticking problems can be quite hard to diagnose so don't be afraid to seek professional help if needed.
What causes brake calipers to stick? To answer your question, I have listed the most common causes below and what you can do about them:
There are grooves located in the caliper that hold the brake pads and let them slide in as you push on the brake pedal and out when you let off. Sometimes the brake pad shims get stuck in the grooves or they just get corroded or debris built up in them. This will cause the pads to not be able to slide in and out correctly and make them stick.
Brake caliper sticking fix: If this is the problem with your brakes, you shouldn't need new calipers - You should be able to just clean them or replace the shims that are causing the problem. In some cases, the metal groove might be getting worn out. If that is the case then the whole caliper assembly would need to be replaced.