Symptoms of a Bad Brake Caliper: Diagnose and Replace

Car brakes are one of the essential safety devices that are installed in cars and there are different kinds of braking structures built into most cars. A few of them are the anti-lock braking system, the disc brake, the drum brake, and the emergency brake.

The brake caliper holds the piston and also suspends the car brake pads over the wheel rotor. The brake piston is linked to the brake pedal through the hydraulic lines. Therefore, if the brake pedal is matched, a hydraulic force is transmitted to the piston and the piston pushes the brake pad against the wheel rotor and causes friction. This friction slows down or brings the car to a stop.

The brake caliper mechanism retracts the brake pad from the wheel rotor immediately after the pedal is released. Over time the brake caliper could start wearing off and will get worse and will require replacement. In this article, we’ll discuss at length the symptoms of a bad brake caliper, diagnosis, etc.

Symptoms of a bad brake caliper

Every bad or failing brake system component will give you a sign before it keeps you on the road, and the brake caliper is no exception. A failing brake caliper will develop series of problems to notify the driver that there’s something wrong with the brakes.

seized brake caliper symptoms

One-sided brake pad wear

If you have a bad brake caliper, there will be situations whereby one of the brake pads wears out faster than the other. Due to the worn-out brake pad on one side of your vehicle, you would likely face braking issues while driving. This is of the common seized brake caliper symptoms.

It is vital to ensure that you change your brake calipers once you notice that one of the brake pads is becoming thinner than the other.

Clunking sound

A bad brake caliper can also produce a loud clunking sound if the caliper bracket responsible for holding the caliper in place breaks. It can result in a situation whereby the brakes on that wheel automatically lock up. If you ever hear noise when braking, endeavor to take your vehicle to an auto mechanic to fix the problem immediately. It is likely a loose caliper bolt symptom.

Squealing noise/metallic robbing noise

If your car’s brake caliper happens to stick or freeze, it can produce a metallic rubbing or grinding noise. This noise is usually heard even when you are not using the brake, unlike the noise from a worn-out brake pad produced when the brake pedal is pressed.

One-sided pulling of the vehicle

Have you experienced a situation whereby you press your car’s brake pedal, and the car pulls to one side instead of slow down to stop in a balanced position? A faulty brake caliper is most likely responsible.

If any of the pistons in the front wheel brake calipers of your car freezes up due to corrosion, dirt, or debris, the brake pad may not come in contact with the brake disc. When this happens, your car will either pull towards or away from the faulty side of the braking system. Also, when a car shakes when braking, a defective caliper may also be responsible.

Brake fluid leak

The hydraulic oil enables hydraulic pressure efficiency, and this pressure enables the brake calipers to function appropriately. If the brake caliper becomes weak or goes bad, there is a tendency to leak hydraulic oil. Brake fluid leakage can easily be noticed on the ground or on the car’s tires.

What happens if you drive a car with a bad caliper 

loose brake caliper dangerous

It is normal for brake pads to wear out over time under normal use but they can also wear out quicker in certain circumstances. Examples of those circumstances are aggressive stop under high speed, and brake pedal riding. Also, if the brake caliper is going bad, it can cause the brake pad to wear out quicker and may result in brake failure.

Suppose your brake structure starts wearing out, it normally sends out a signal to you. If you ignore these signals, you might be heading to a disaster that might be fatal. Always observe and monitor your car brake system for abnormalities like loud squealing and Abs Light On.

Ensure you fix any potential breakdown down of your brake system, like brake pad wear off and unresponsive brake caliper. Continuous usage of a faulty brake caliper is dangerous and can cause catastrophic damages to the entire brake system. Below are some common effects of driving with a bad caliper.

Damage of brake Wheel calipers and rotors

The brake system is made of integrated moving components, therefore if one of the components wears off, other devices connected with it will start wearing off too. For instance, if your brake pad wears to a particular extent that the metal is exposed, it will start wearing down the wheel rotor and cause severe damages to it within a short period.

What happens is that when the brake pad squeezes and makes contact with the wheel rotor to halt the car, it grinds against the rotor. If the brake pads are not replaced, the grinding continues to occur each time the brake pedal is matched and in a short period, the brake rotor will be damaged. The grinding noise is a clear indicator that something is wrong.

Whenever the brake pads are pushed against the brake disc, it generates heat. And the heat damages the seals on the piston and makes it get stuck. This is what causes brake calipers to fail to return when the brake pedal is released.

The increased brake response period

The efficiency of your brake pads is completely reduced when they are worn out. Therefore, it is necessary to always observe your brakes and take note of the time they take to respond. Note that if your brake pad starts wearing off, your brake may not answer once you depress it. You may have to pump it before it’ll engage.

Some of the consequences of driving with a bad caliper include slippery brake, car sliding one corner when you apply the brake. Finally, the brake bad may stop engaging and disengaging the brake rotor as built by the manufacturer and it might result in brake failure.

Car trembles when the brake is applied

Car vibrations or trembling occur due to so many reasons, especially from the wheel area. Therefore, here comes an important question; can a bad brake caliper cause vibration? Yes, it can, because a vehicle whose brake is working properly should respond smoothly when the brake is applied.

So, when the pad and the rotor have been damaged or worn out excessively, they could start causing vibrations in the car movements. Your steering may also vibrate when you try to slow down or make a stop.

Tiers may start wearing down

If you fail to fix your car brake mechanism when some parts are bad, then your tires will also start wearing down. When you have uneven deceleration amongst your tires due to a bad brake caliper on some of the wheels, then some tires will wear off quicker. A bad caliper also causes you to slam your brake pedal repeatedly to achieve a stop.

How do you diagnose and replace a bad brake caliper

It is uneconomical to condemn your brake caliper or any part of your car brake mechanism without proper diagnosis, therefore, you should conduct a proper diagnosis to ascertain the part that is damage.

Learning how to diagnose a bad brake caliper is not difficult as you may presume. Therefore, if you are willing to do it yourself, then get your brake calipers tools and follow these procedures;

Check for Leaks

If you have a spongy or a low pedal, the first thing you should suspect is a leak and one of the commonplaces to inspect is the caliper. You may also suspect a bad Master Cylinder but first check for leaks all-around the brake system.

Inspect the caliper piston, the hydraulic lines, the bleeder screw, and the master cylinder. When you have discovered the leaking point, then you service or change it out.

Inspect Brake Pads

Unbalanced wear out of brake pad can be symptoms of bad caliper slide pins. Conduct proper diagnosis by raising your vehicle at a safe height and add support to it. Unbolt the caliper, pull it out, then, inspect the brake pads for wear. If you notice unbalanced wear out, a bad or rusted sliding pin could be the culprit.

If the caliper pins are stuck or don’t move freely, clean and lubricate them to resume normal operation. If you discover unbalanced wear out of the brake pad but the sliding pins are in good condition, you need to diagnose and ensure the caliper pistons are moving freely.

Diagnose Piston function with a Tool

A stuck piston or that has pulled out of its bore can initiate brake drag, the unbalanced wearing of brake pad, and vehicle sliding to a corner. Try the few steps below to diagnose this condition:

  • Raise your car to a safe height with a jack and jack stand and attempt to rotate the tire by hand. IFf it is hard to rotate, then you could have a stuck caliper that is pressing the brake pad against the wheel rotor.
  • Proceed to diagnose the caliper by pressing the piston back to its bore with your hands
  • If it doesn’t work proceed on decoupling the entire wheel assembly
  • Loosen the caliper from the bracket and pull it out and do not loosen the hose.
  • Use C-clamp to press the piston back to its bore and monitor the master cylinder so, it doesn’t push fluid out of the reservoir. If the piston is bad or requires servicing, it will be hard or impossible to set back into the bore.
  • Also, try to loosen the bleeder and press the piston in, if the piston still refuses to move, then know that the caliper is bad.

Get an assistant to assist you to diagnose Piston functions

You need to get an assistant you diagnose your piston functionality especially when it’s stuck. A stuck piston can cause a low brake pedal, therefore if you have an assistant, you can diagnose the issue with ease.

  • Raise the vehicle to a safe height and suspend it with a jack, then lose out the wheel assembly
  • Let your assistant match and release the pedal while you watch
  • Observe if the piston travels in and out of its bore properly to confirm the status of the piston
  • Also, check brake fluid leakage around the hoses and the caliper.

Final Words:

Driving with a bad caliper is wrong and very dangerous, especially when they have excessively worn out. A bad caliper can cause damage to the wheel rotor, wearing of car tires, car vibration, and reduced brake response time, and it may even lead to a severe road accident. Therefore, always watch out for symptoms of a bad brake caliper and fix it on time.

Also, conduct a proper diagnosis on your brake system to ascertain the particular damaged part and service it or replace it if needed. Inspect for leaks, inspect brake pads, inspect piston and hydraulic lines, and service or replace them. Always call your mechanic to carry out proper diagnosis and repair unless you understand the issue you’re facing at the moment.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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