Anyone who has a car knows that the brakes are one of the most vulnerable parts of the car, and if you have a great deal of trouble with your brake callipers, then you may need to troubleshoot them quickly in order to prevent an accident. If your car is pulling to one side, then this indicates that one of your brake callipers is seizing up, and this can be a serious problem which needs to be dealt with as quickly as possible. In order to remove the problems with your callipers, you will need to troubleshoot the problem, and try and find an easy answer which will get your car working properly again.
What causes brake callipers 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 calliper 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.
The brake calliper 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 calliper. 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 calliper 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 calliper while replacing the brake pads. If it gets torn, then rust and other debris can build up inside the calliper and cause the piston to not slide smoothly. This can cause the brake calliper to stick. Sometimes you can find brake calliper rebuild kits, but most of the time the only way to fix this type of problem is to replace the brake calliper assembly. Take your vehicle to an accredited RMI workshop like Astro Brake!
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 calliper to stick and make the vehicle pull to that side. This can be a tough problem to diagnose even for a seasoned mechanic.
The best way to avoid brake callipers from locking 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 calliper(s).
Depending on how much mileage you clock up, most callipers will last the life of the vehicle or close to it. Sometimes brake calliper locking problems can be quite hard to diagnose so don’t be afraid to seek professional help if needed.