Brake seizure is something every car owner will likely experience at least once in their lifetime.
Car brakes may seem simple, but in fact, they are often a fairly complex system that requires a lot of maintenance.
In this article, we will discuss the causes of sticking brake calipers and how you can avoid them.
Common symptoms of a sticking brake caliper are a bad smell, smoke from the wheels, and high fuel consumption.
But what can cause a sticking brake caliper?
Here is a list of the 7 most common causes of a sticking brake caliper.
1. Rusty Caliper Pistons and Piston Boot
The caliper pistons are an essential part of the braking system. They push the brake pads against the brake disc so the car slows down.
The brake caliper pistons are surrounded by a rubber boot to prevent dust and other particles from entering the braking system.
It is quite common for this boot to be damaged, allowing water and other dust to enter the piston. This will cause the piston to rust and, eventually, it will stop moving completely – which will lock the brake pads against the brake disc.
Check for any damage around the caliper boot and try to lift it a little to see if you can see any rust.
If it is rusty, you can push the piston and clean it a bit – but don’t forget to replace the boot, which can be difficult without knowing how.
Replacing the entire caliper is often not very expensive, and I actually recommend it instead of refurbishing it.
2. Rusty and Stuck Brake Pads
Rusty Brake Pads
The second most common cause of a sticking brake caliper is actually rusty brake pads. The brake pads have their guides, which need to be lubricated so that the brake pads slide easily back and forth on the brake caliper bracket.
When dust and rust collect on these bracket slides, the brake pads get stuck in the brake pad bracket and push against the brake disc.
To fix this problem, you need to remove the brake pads and clean the brake pad bracket with a file or sandpaper and lubricate it with copper paste or something similar.
3. Dirty Caliper Guide Pin
The brake caliper guide pins are located on the brake caliper bracket and help the caliper slide back and forth when you brake.
Usually, these guide pins will get stuck due to rust, which will prevent the brake caliper from working properly and, consequently, cause the brakes to seize.
These guide pins are surrounded by rubber boots to protect them from water and dust. Check the rubber boots and remove, clean, and lubricate the guide pins again.
They can be a pain to remove when they have been stuck for a while – so a torch is essential to heat them up when you try to remove them.
4. Parking Brake Cables
Rear brake caliper with cabling
If your sticking caliper problem is coming from the rear of the vehicle, there’s a good chance the parking brake is causing the issue.
Many modern cars do not have a parking brake inside the brake disc but on the brake caliper. Water and other dust can get into the parking brake cables and cause them to rust.
This will prevent the brake calipers from releasing properly when you release the parking brake.
To fix this, you can try lubricating the parking brake cable and the caliper arm and moving it back and forth a hundred times to see if it improves. In the worst case, you need to replace the parking brake cables or the caliper.
5. Broken Brake Hose
The brake hose allows brake fluid to flow to the braking system and back to the master cylinder. However, if there is a small break in the brake hose, the brake fluid will flow to the brake pistons but not return.
This will cause the calipers to stick. This is not a very common problem, but I have noticed it in some cars. If you have tried everything and the problem persists, you should try replacing the brake hose.
6. Dirty or Old Brake Fluid
Dirty Brake Fluid
Dirty or old brake fluid is actually the main cause of many brake problems. Brake fluid absorbs water from the air and therefore should be replaced every 1 or 2 years.
If you don’t replace it, it will contain a lot of water, which will cause your brakes to rust from the inside.
How to Prevent a Brake Caliper from Sticking
Most of these problems should not happen as often if you regularly take care of your brakes. There are certain things you can do to avoid these kinds of problems in the future. Here are the most common ones:
1. Change the brake fluid every 1 to 3 years – will prevent the braking system from rusting from the inside.
2. Clean the brake pads, guide pins, and pistons every 2-3 years – or at least do it properly when you replace your brake pads or discs.
3. Brake hard at high speed sometimes – some may think that never using your car’s brakes is a good thing, but it’s the opposite. If you never use the brakes too hard, they will get stuck after a while.
Many people drive short distances and never use their brakes properly. You need to use your brakes at high speed several times a year to prevent them from seizing completely.
4. Use your parking brake even if you have an automatic transmission – Another common problem is that you never use your parking brake if you have an automatic transmission. This will cause the parking brake cables or bracket to seize the one time you use it.