Brake Caliper sticking (Causes and how to prevent it)

Most car owners will have to deal with stuck brakes once or twice in their life.

Although car brakes may seem simple, they are often complex and require a lot more maintenance.

We will be discussing the causes of sticky brake calipers as well as how to prevent them. So let’s begin with what could cause a sticky brake caliper?

Most common reason for a stick brake caliper are a rusty piston and damaged piston boots. Sticky brake pads pressing on the brake discs can cause it. If it’s a rear brake caliper, it could be a faulty parking brake cable.

However, some other more rare things could cause a sticking brake caliper, so let’s take a look at these also. Below is a list with more details about the seven most frequent causes of sticky brake calipers:

What causes a stuck brake caliper?

1. Rusty Caliper Pistons & Piston Boot

They are an integral part of your brake system. The brake pistons push against the brake disc, reducing the vehicle's speed.

Rubber boots are placed around the pistons of brake brake calipers to keep dust and particles out of the brake system.

The boot is prone to being damaged and water or other dust can get into the piston. This will cause the piston to start rusting, and finally, it will stop moving completely – which will cause the brake pads to get stuck against the brake disc.

You can check for damage to the caliper boots and lift it slightly to look at if there is any rust.

If it is rusty, you can push the piston out and clean it a little bit – but do not forget to replace the boot, which can be difficult without the knowledge.

The cost of replacing the entire caliper can often be affordable, and it is something I would recommend over renovating.

2. Rusty & Stuck Brake pads

A rusty brake pad is the next most frequent cause of a stuck brake caliper. For the brake pads' smooth glide on the bracket of the brake caliper bracket, they need to be properly lubricated.

Dust and rust can build up on the bracket slides and the brake pads may get caught in the bracket. This will push the brake disc.

This can be fixed by removing the brake pads, cleaning the bracket using a file or sandpaper, and then lubricating it with copper paste.

3. Dirty Caliper's Guide Pin

These pins, located on the brake bracket, allow the brake lever to move forward or backwards while you brake.

These guide pins can become stuck from rust and prevent brake calipers functioning correctly. This will cause stick brakes.

Rubber boots are placed around the guide pins to keep them dry from dust and water. You can inspect the rubber boots to make sure they are clean.

They can be a pain to remove when they have been stuck for a while – so a torch is a must to warm them up when trying to remove them.

4. Cables made of parking brake steel

If your sticking caliper problem comes from the vehicle’s rear, there is a big chance of a problem with the parking brake.

Modern cars don't have the handbrake on the brake disc, but instead on the brake pedal. The handbrake wires can rust from water and dust.

The brake calipers will not release correctly when the handbrake is released.

You can fix it by lubricating the handbrake cables and the arm of the caliper. Then move the car backwards and forwards a hundred more times until it improves. You may need to change the parking brake cables and caliper in the most extreme cases.

5. Broken brake hose

Brake fluid flows to the brake hose to reach the brake system. The brake fluid flows to the pistons of the brakes, but will not flow back if the brake hose is damaged.

The calipers will stick to the car. It is not an issue that I see often, however it has been seen in some cars. You should replace the brake hose if you've tried all other options.

6. Filled with old or dirty brake fluid

Brake problems are often caused by old or dirty brake fluid. It is important to replace brake fluid every 1 to 2 years because it draws water from air.

It will be leaking if you don't replace it. This will cause your brakes to rust.

How to Avoid a Sticky Brake Caliper

These problems don't have to occur so frequently if your brakes are maintained regularly. These problems can be avoided by taking preventative measures. The most frequent are:

• Change brake fluid approximately every 3 to 5 years – will prevent the brake system from rust from the inside.
• Every 2 to 3 years clean brake pads, guides pins, pistons. – or at least do it properly the times you replace your brake pads or brake discs.
• Sometimes, you need to brake hard when driving at higher speeds – some may think that never using the brakes on your car is a good thing, but it is the opposite. The brakes will become stuck if you don't use them often.
• Many people don't use their brakes correctly, even though they drive short distances. To prevent your brakes from becoming stuck, you should use them at high speeds several times per year.
• You can use your parking brake regardless of whether you have an automated transmission – Another common problem is that you never use your parking brake if you have an automatic transmission. It will result in the bracket and cables getting stuck on the first time that you use the parking brake.