What Causes Brake Squeal?

Find out what causes brake squeal and how to stop brake squeal

There’s nothing worse than coming to a stop and hearing that shrill, piercing sound of your brakes squealing.

But what actually causes this noise and how can it be prevented?

This is something we get asked on a day-to-day basis, so we’re writing this article to give you the answer.

This is actually a very common problem that a lot of people don’t understand.

Most people when they hear their brakes squealing, they do nothing and expect it to go away. Sometimes, people have their music too loud to even notice it.

However, not resolving brake squeal can be dangerous and cost you in the long run.

What Causes Brake Squeal?

Squealing brakes are a sign of one of the following conditions.

  1. The friction material is effectively gone and the backing plate is being jammed against the brake rotor (worn brake pads).
  2. Glazed pads and rotors.
  3. Lack of brake pad insulation
  4. Broken anti-rattle clips

 

Worn brake pads

Squealing is the result of extremely high-frequency vibration between the pads, the caliper piston, and the brake rotor. A brake pad is compromised of steel backing with friction material attached to it. When you apply the brakes, hydraulic pressure is produced causing the brake pads (via brake calipers) to clamp down on the brake discs (rotors) causing friction. The friction caused by the pads clamping onto the discs is what slows down and brings your vehicle to a stop.

When the friction material on your pads wears down, the time has come to change your brake pads.

Glazed brake pads and discs

Brake squeal can also happen when the brake calipers are sticking and the brake stays partially applied. When this happens the brake pads are in constant contact with the disc. This produces excessive friction and heat. Overheated brake pads can harden and crystallise.

Glazing doesn’t just occur on brake pads, it can also occur on brake discs. If this is the case, the squealing is the result of these hardened surfaces coming into contact with each other.

Lack of brake pad insulation

When a vehicle is new, insulation shims are placed against the steel backing of the pad effectively insulating it from the brake caliper. When the shims eventually wear out, this can also cause squealing.

Broken Anti-rattle clips

Brake pads are held in place on the caliper by pad stays. Anti-rattle clips are used to secure the pad to prevent it from vibrating or rattling when you apply the brakes. If your anti-rattle clips are broken, the brake pads vibrating will cause the squealing noise you can hear.

How to Stop Brake Squeal

So, we’ve identified the causes. We now need to stop the brake squeal from happening.

  1. Replace worn out brake pads with new brake pads
  2. Clean your existing brake pads
  3. Replace or clean your brake discs if they’re rusted.

 

ChrisFix explains how to stop your brakes from squeaking in this great video (see below)

When Should You Replace Your Brake Pads?

Changing the brake pads of your vehicle is a major adjustment to your vehicle to keep it safe.

When should they be replaced?

  1. If your vehicle’s brake pedal feels spongy or springy when applied
  2. Poor braking
  3. Your vehicle judders when braking
  4. Brake Squeal

 

Replacing your brake pads is a cheap and effective way of keeping your vehicle roadworthy and safe and should be something that is not overlooked. Check your brake pads today to keep your vehicle running safely, smoothly and legally.

Milner Off Road stock a wide array of 4×4 brake pads for different vehicles, so if you suspect that your brakes may be on their way out, we can help.

Simply enter your reg number here to see our range of 4×4 brake pads and other parts, and if you have any questions please don’t hesitate to get in touch or leave a comment.

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