Why Are My Disc Brakes Squeaking?

Disc brakes are a popular choice for many bike enthusiasts due to their superior stopping power in all weather conditions, as well as being extremely reliable and durable.

However, it’s not uncommon for disc brakes to make a squeaking noise if they’re contaminated or worn down, for example.

If you find yourself in this situation, do not worry! We have compiled a list of possible reasons why your disc brakes are squeaking, and quick fixes to each of these problems.

Your disc brakes could be squeaking because:

The pads are contaminated
The pads are worn down
You are using metallic pads
The disc rotor is crooked
The brake calliper is misaligned

1.The Pads Are Contaminated

If you can hear a loud, consistent squeaking noise whenever the brake is applied, then contamination is likely to be the problem. Contaminants (such as oil or lubricant) cause the pads to lose grip on the rotor, which can cause vibrations, resulting in squeaking.

The best way to know if your brake pads have been contaminated is if you rode through oil on the roads, or had some sort of suspension or brake fluid leak. A quick visual check around your brake calliper can reveal this. If you feel or see oily film, chances are it’s been contaminated.

Contamination may also occur if you accidentally get any lubricant or degreaser on them.

To fix:

The good news is that contaminated disc pads can be fixed, and there are a number of methods you can follow to do so.

If the pad has been contaminated recently and the oil hasn’t yet been absorbed, clean them immediately with a clean rag and isopropyl alcohol. If the pads are already contaminated, remove them from the calliper and carefully sand down the outer layer with a fine-grained sand paper. However, if your brake pad is saturated in chain lube, it’s probably best to replace the brake pads completely.

You can also burn off the contaminants using a blow torch. Now, it might sound a little crazy but hear us out – fire is an excellent way to clean pads. To begin, bring the pad to the flame and make a number of passes over it. With two or three passes over the flame, the oil should burn off completely. To avoid overheating, only hold the pad over the flame for a couple of seconds.

When cleaning your bike next, either cover your disc rotor and calliper or ensure you spray degreaser on the chain in a way that stops it getting onto the rotor. Alternatively, you may choose to use a chain-cleaning device, such as the Dirtwash Chain Cleaning Machine, to virtually remove the risk of pad contamination.

2. The Pads Are Worn Down

Your pads may also be making a racket if they’re worn down to the metal, as the disc pads will be rubbing against the disc rotor.

To fix:

The best way to check the condition of your disc pads is by removing the wheel and checking how much pad material is left. If they are clearly visibly worn down, it’s time to replace them.

When fitting new disc brake pads, ensure you thoroughly clean the disc rotor and calliper to stop any old contaminants (such as oil or degreaser) finding their way onto the new pads and to allow for the best bed-in procedure.

3. You Are Using Metallic Pads

The type of disc brake pads you’re using may also be affecting the noise. Typically speaking, metallic brake pads tend to be louder than their organic counterparts, resulting in a noisier ride. Metallic pads also put more stress on the brake system, adding more strain and wear on the brake rotors.

To fix:

If you currently have metallic brake pads, you may decide to switch to quieter, organic brake pads.

However, if you do decide to change your disc brakes pads. remember to use a new disc rotor that’s compatible with the pad material to ensure optimum performance. You should make sure you use the correct disc brake pad for the overall braking system.

4. The Disc Rotor Is Crooked

If you can hear squeaks while riding at regular intervals, it is likely to be a calliper alignment issue or a crooked disc rotor that is causing your brake pads to rub as you cycle.

To fix:

To avoid this problem in the future, never lean your bike by its disc rotor. Although this sounds obvious, it’s easy to accidentally bend disc rotors when transporting the bike, for example when loading it into the car.

To fix a crooked disc rotor, discover where the bend is in the rotor and attempt to bend it back with an appropriate rotor-bending tool. Be extra careful as too much force will bend the rotor too far back the other way. You should also avoid touching the disc rotor with your fingers because the oils on your skin can contaminate the disc rotor.

If your rotor is bent in a number of areas, it’s unlikely you’ll be able to make it straight again. In this case, it’s easier to replace the rotor.

5. The Brake Calliper Is Misaligned

Your disc brake may also be rubbing due to a misaligned brake calliper. If your calliper isn’t centred properly, the disc will rub against either the inside of the calliper body or the brake pad.

To fix:

The best way to solve this problem is to slightly loosen the two bolts that hold the calliper to the frame. Don’t completely loosen them, but loosen them enough so the calliper can move.

Now the bolts have loosened, spin the wheel and pull on the respective brake lever. Then, without releasing the brake lever, equally tighten the two bolts back up to the relevant torque spec and, hopefully, the problem is solved.

And there you have it! Hopefully these points have helped you discover the cause(s) of your disc brake squeaking. Learn more about brakes, including how to service disc brakes, here.

We’re Mackadams, the trade site for bike parts delivered fast. For more top tips from our bike experts, head over to our blog page or get in contact with us on 01686 611 370.

Written by Kate for bike parts supplier – Mackadams.