Ever feel your vehicle pull to one side when braking? Or notice a burning smell from your wheels? These signs (and others) often point to a stuck brake caliper, a common issue that can create safety hazards.
If you’re facing problems with a brake caliper sticking or stuck, you need to know the common symptoms to look for as well as the most likely causes so you can get the issue fixed.
See Also: 4 Causes of Brake Shudder
Common Symptoms of a Stuck or Frozen Brake Caliper
#1 – Vehicle Pulls to One Side
With a stuck or seized brake caliper, your car will have the tendency to pull towards the side that has the sticky caliper. It will be similar to if you had a bad alignment but usually more serious. This will happen not only when braking but when you’re simply driving.
Continuing to drive when you’re vehicle won’t stay straight is incredibly dangerous. You or a professional mechanic should inspect your brake calipers right away to rule out that a bad caliper isn’t to blame. Otherwise, your car likely needs a wheel alignment done.
#2 – Car Slows Itself Down
When you have a sticky brake caliper or calipers, they are often at the point where they are making your brake pads to have constant contact with your brake rotors. This in turn makes it feel like you are braking even though your foot isn’t on the brake pedal.
In addition, you will quickly wear through brake pad material which can result in high pitched sounds or grinding after enough brake pad material is used up. Confirm your brake calipers are not stuck; otherwise replace the caliper or any related parts as needed.
#3 – Excess Heat From Wheel Area
Because a frozen brake caliper will be applying constant pressure to the back of the brake pad, which in turns applies constant friction to the brake rotor, heat is a result of this friction. The longer you drive with a stuck brake caliper, the hotter it will get in that area.
If you do a slow walkaround your vehicle after stopping, you should notice extra heat coming from a specific wheel if you place your hand near it. This is often a telltale sign you’ve been driving with a seized caliper.
#4 – Bad Gas Mileage
Having bad fuel economy can be the result on many different problems including your calipers. As mentioned above, a stuck caliper will result in unintended braking making your engine work harder to keep at its speed which results in more fuel being used.
The symptoms of brake caliper sticking is: Your vehicle will often pull more toward one side when you apply the brakes. You also may notice the brake pedal not coming back up all the way after you take your foot off from it. If you’ve experienced any of these symptoms, then you definitely have brake caliper sticking problems.
#5 – Burning Smell
As already mentioned, a sticking brake caliper constantly drags and rubs against the brake rotor, even when you’re not applying the brakes. This friction generates intense heat that can cause the caliper, brake pads, and rotor to overheat quickly. The burning smell often comes from these overheated components grinding on each other.
This constant friction also accelerates wear on brake pads and rotors. As they wear down, the metal backing of pads and rotors rub together, which smells like burning chemicals or rubber. Built up debris and brake dust on the calipers and rotors can even ignite from the excessive heat, contributing to the burning odor.
Top 3 Causes of a Seized Brake Caliper
It is not too common to have sticking brake calipers, but when they are, there are only a handful of causes that could be responsible for it. Here are the three most common.
Related: 3 Causes of a Stuck Parking Brake
#1 – Brake Caliper Piston and Brake Hose
The common cause for a brake caliper sticking is with the caliper piston and the brake hose. The piston has a rubber boot on it which lubricates and protects it. But if this rubber is torn, it will cause debris and rust to form inside the caliper which means the piston’s sliding abilities will diminish.
The rubber boot of the caliper piston is often torn from careless mechanics who are installing new brake pads but it can also deteriorate due to age.
As for the brake hose, it will just wear out over a period of time. Once the hose beings to crack or break, it will cause brake fluid to flow onto the pistons and slow down the vehicle. The worst part is the fluid won’t be able to make it back to the master cylinder, which will make the caliper stick.
#2 – Brake Caliper Slides
And another common cause is with the caliper slides. You see, each caliper has grooves where the brake pads slide into when you step on the brake pedal. When you take your foot off the brake pedal, the brake pads slide out of the grooves.
But if there is debris or corrosion built up in the grooves or on the brake pads, the pads will end up getting stuck in those grooves. This means the brake pads won’t slide out of the grooves after you take your foot off the brake pedal, resulting in the brake calipers feeling sticky when you apply the brake.
Read also: Ceramic vs Organic Brake Pads
#3 – Brake Caliper Bolts
And another possible cause for a frozen brake caliper is with the caliper’s bolts. These bolts are made to slide as well and they can easily become sticky if they are too dry and not lubed up periodically.
The bolts are made with a protective rubber layer to trap the lubricant inside the bolt but this rubber can easily tear and cause the lubricant to spill out. This most often happens by accident when mechanics are installing new brake pads into a vehicle.
Once the bolt dries out, it will cause rust and debris to build up which will further deteriorate the sliding mechanism it has.
Case Study: All Brake Calipers Completely Stuck
If you’re facing a problem where your vehicle cannot move at all due to the brakes being totally stuck, you can read my personal experience below. Maybe you’re having the same problem as I did.
I’ve personally encountered this problem where the symptom is that the car cannot move due to all brake pads holding very tightly the rotor discs. So I began to narrow down the problem one by one. Here’s the diagnostic process I went through before finally figuring out the cause.
- Check caliper and piston –> OK
- Check the brake hoses and line –> OK
- Check the brake fluid –> OK
- Check the brake line connector –> OK
- Check the brake master cylinder –> OK
- Bleed the brake fluid –> OK
Result = Problem Still Exists
Then I finally removed the brake booster and measured the length of push rod. I found that the push rod was over the standard length, so that the rod always pushed the master cylinder and gave brake fluid pressure to the each caliper pistons on the brake discs. This caused all of the calipers to be stuck making the vehicle impossible to move.
To fix the problem, I simply adjusted the push rod to the standard length and the problem was fixed.
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