Why Do Brake Calipers Stick?

While not exactly a common occurrence, brake calipers can stick at times, causing a serious safety issue.

The sensation of sticking calipers feels like your brakes just don’t release all the way. If your calipers are sticking, your vehicle may feel as if its' hesitating to move.

If you believe your calipers are sticking - or want to rule out the possibility - this guide is for you.

Common Brake Caliper Sticking Causes

There are a variety of common things which may be causing the brake calipers to stick. Here is a short list.

Caliper Slides

Caliper Slide

Brake calipers have grooves that hold the brake pads and these grooves let the pads slide in as you push on the pedal. Over time, these grooves can become rusted over or there may be debris preventing the pads from sliding.

An easy way to see if this is your problem is to remove and carefully examine the calipers. If you see debris or rust, you can use a cleaner to remove the obstacles. If the grooves are simply too worn, you may want to buy new calipers.

Caliper Bolts

Another culprit can be the caliper bolts. Like the caliper, there are grooves on them that need to stay lubed. The bolts come with protective rubber boots to keep this lubrication in, yet sometimes they can wear down. Also, some mechanics won’t lube the bolts when they re-install them. Putting them back dry causes the lubrication to break down as well.

Dry bolts can build up debris or rust faster and, like the caliper slides problem, can cause the calipers to stick. In order to fix this problem, you can sometimes take the bolts out and re-lube them. Or you can order new ones. In extreme cases you may need to order a new caliper if the bolts aren’t available.

Brake Hose

Brake Hose

Over time, brake hoses can wear out internally. When this happens, your brake system will not get the right amount of fluid to operate correctly. The problem is a small piece of the hose breaking off and creating a sort of valve. This valve will only let brake fluid flow one way.

When brake fluid doesn’t flow correctly, the brakes will be slow or simply won’t return back to normal. This is due to the fluid not reaching the master cylinder.

Since the brake hose looks fine, this problem is often hard to diagnose. One way to see if you have this problem is to raise the vehicle up and step on the brakes. Then, let off and try again. If one of them won’t turn, open the bleeder valve and see if brake fluid shoots out. Brake fluid shooting out will tell you if there is a lot of pressure built up in the braking system. This pressure could be caused by a bad brake hose.

Brake Caliper Piston

Like the brake hose, over time the caliper piston can wear down and become torn. The piston has a rubber boot around it and if this becomes torn or worn down, debris and rust can build up. This debris/rust can slow down the piston and by extension the caliper itself.

Fixing this problem is fairly straightforward. You can either shop around for a brake caliper rebuild kit or buy a new caliper.

Tips to Avoid Brake Caliper Sticking Issues

While the sticking issue is pretty rare, there are several things you can do to prevent it from happening.

  • Replace your brakes regularly by following the maintenance schedule which came with your vehicle
  • Inspect the caliper while doing brake maintenance and make sure you check the grooves for debris/rust
  • Replace brake lines at the first sign of wear

Your brake caliper should last for the life of the vehicle with proper maintenance. By following these tips, you shouldn’t have any issues.

Questions?