Causes for a brake caliper sticking
Your brake system uses fluid to exert pressure on a piston within the brake caliper, pressing into the brake pads and creating friction between the pad and the brake rotor. The friction generates heat, but under normal operation, that heat dissipates quickly, and your brakes will get you stopped safely.
If you notice that your brakes are emitting grinding noises, the vehicle is pulling to one side, or if you smell burning, it could mean that one or more of your calipers is seized or sticking.
What is causing your brake caliper sticking? Learn how to recognize the symptoms and how to fix a stuck brake caliper with AutoZone.
What causes your brakes to be stuck?
- Immobility. The most common cause of stuck brakes is immobility. If your car sits for long periods of time, you may notice slightly stuck brakes when you first get going, but this will typically work itself out in the first few moments of driving.
- Damp climate. If you live in a damp climate, it’s also possible that corrosion will creep into the system during an inactive period. Your brake rotors can rust and stick to the pads, your slider pins can become stuck, or your caliper pistons can seize. Again, in most situations, a little cautious driving with a few brake checks thrown in can clear less severe symptoms up.
- Corrosion. Another common cause of sticky brakes is corrosion within the caliper pistons due to old brake fluid. Brake fluid is typically glycol-based and will protect all the metal parts in the brake system from corrosion, but if there is some moisture in the system, that water can lead to corrosion in the brakes, and especially in the caliper piston that activates the brake pads. It’s a good idea to change your brake fluid every couple years to avoid the damage caused by the moisture that will inevitably enter brake fluid.
- Handbrake. Your handbrake can also be a cause for sticking in the rear brakes. You can avoid this issue by lubricating your handbrake cable and mechanism occasionally.
Common symptoms of brake caliper sticking
Some of the symptoms, like a burning smell or grinding noises, are very obvious but there are some that are less so.
Here are a few symptoms of a sticky brake caliper:
You can hear a grinding or squealing noise coming from only one of your wheels. This indicates that you may have a worn brake pad and if it’s only coming from one wheel it may indicate a bad caliper. If all your calipers are good, your brakes should wear more evenly, requiring replacement at the same time.
On the same track, if you do a visual inspection of the brakes and notice that either the inside or outside pads on one caliper are wearing much faster, that is probably related to a sticky caliper piston or caliper slide pins.
If you notice that the car feels sluggish, or if it tends to pull to one side, you may have a seized caliper. If that happens, do a visual inspection to check for pad wear and obvious signs of a sticky caliper.
A burning, acrid smell is a final warning, and one that you should take seriously because if your brakes are overheating enough to smell like they’re burning you could start a fire at worst and damage the wheel hub and braking system at the very least. Pull over and conduct a visual inspection.
Signs of a bad brake caliper
Doing regular maintenance work on your own car is so important because it gives you an opportunity to visually check for wear items before they become an issue. Doing an oil change is a chance to check for new leaks or issues within the engine bay and under the vehicle. When you are switching winter tires over to summer tires you can do an inspection on your brakes, suspension, and drivetrain components.
If you notice that the brake pads at one wheel are wearing differently than the rest, especially if the inside or outside pad is heavily worn or worn at an angle, is a signal that something is wrong with your caliper. You will want to replace the pads and maybe even the brake rotor, but you should also address the underlying issue of the bad caliper.
How to fix it
If you find that one of your calipers is sticking or completely seized, you can either replace the caliper or rebuild it yourself. Either way, you will need to flush and refill the brake fluid.
The easiest route is to purchase and install a new brake caliper. It’s a good idea to install brake calipers in pairs, so do both rear calipers or both front calipers at the same time. The price of a new or rebuilt brake caliper will range from as low as $35 to several hundred dollars, depending on the make, model, and part grade. If your caliper piston is very corroded, you will definitely want to go with a new or rebuilt caliper.
If you aren’t afraid to get your hands dirty and your caliper isn’t too corroded, a caliper rebuild is well-within the abilities of most home mechanics and it’s much less expensive, with most rebuild kits coming in at less than $10. You’ll need to purchase the correct caliper rebuild kit for your vehicle, which will include some seals and gaskets, and you’ll also want some brake cleaner.
Take apart the caliper and clean off all the corrosion you can see or feel, replace all the rubber parts so that moisture can’t infiltrate your braking system, and reassemble. Use a silicone-based brake lubricant for any of the moving parts that won’t come into contact with brake fluid, like the caliper slider pins.
Once you’ve reassembled the caliper and reinstalled it, flush all the old brake fluid and bleed the brake system.
Whether you decide to do the rebuild yourself, or if you go with a new caliper, you can find the right caliper and parts for your car at AutoZone.