How To Fix Squeaky Brakes
Corner Park Garages, Swansea and Cardiff
March 20, 2019 at 10:02 AM
Brakes are one of the most important parts of any vehicle, so ensuring they work properly is imperative. Modern brakes consist of a cast-iron disc squeezed between two brake pads which are held in place by callipers.
When you press the brake pedal, hydraulic pressure causes the brake pads (via the callipers) to clamp down on the brake disc (also known as the rotor) creating friction. In turn, this scrubs speed from the tyres making the car slow down and eventually stop.
WHAT CAUSES SQUEAKY BRAKES?
It's natural for brakes to make noises from time to time as a result of different driving conditions - for example, if it's dusty or humid. Similarly, the temperature of your brakes and how hard you press on the pedal can cause them to make an audible sound.
If the squeaky noises from your brakes are brief and sporadic it's normally nothing to worry about and easy to explain. As long as the brakes are still working properly, you shouldn't need to visit a garage. However, if the noises are loud and frequent, it indicates a more serious issue.
The main causes of squeaky brakes are:
- Collection of moisture from rain, dew or condensation
- Thinning brake pads
- Cheap brake pads with high metal content
- Loose parts
- Glazed brake pads and discs
HOW TO FIX SQUEAKY BRAKES
In order to stop squeaky brakes, you need to know what is causing them. It's likely to be one of the reasons outlined above.
COLLECTION OF MOISTURE FROM RAIN, DEW OR CONDENSATION
When your car sits on the road overnight, the surface of the brake discs are susceptible to collecting moisture from rain, dew or condensation - depending on the weather.
This moisture causes a thin layer of rust to form on the brake disc surface. As the brake disc turns, the brake pads scrape the rust off which can get caught and embedded on the leading edge of the brake pad causing a squeak when you press the brake pedal.
Squeaky brakes as a result of moisture typically occur in the morning and usually stop after a few minutes when the brake pads have had a chance to warm up a little, or the thin layer of rust has worn off.
The only way to 'fix' this type of squeak is to protect your car from being exposed to overnight weather conditions by keeping it in a garage.
THINNING BRAKE PADS
When your brake pads are almost worn out or getting extremely thin, you will start to notice a squeaking or squealing noise when you press the brake pedal. This is caused by the brake-wear indicator rubbing against the brake disc.
Manufacturers deliberately place a small piece of soft metal - the wear indicator - into their brake pads to warn you that they need replacing. Wear indicators are attached in different ways; some manufacturers weld them on, use a rivet, or use a push-on clip attached to the edge of the brake pad backing.
Once your brake pads reach this point, they need to be replaced. This is a job that you can do yourself if you buy replacement brake pads, or if you're not confident enough, it's a simple job for a trained mechanic.
CHEAP BRAKE PADS WITH HIGH METAL CONTENT
Most cars use semi-metallic brake pads which are comprised of metal shavings of copper, steel, graphite and brass bonded with resin. They will also contain organic materials such as glass, Kevlar and rubber.
However, cheaper brake pads have a much higher metal content. As a result, there are larger pieces of metal on the brake pad surface which scrape against the brake disc causing high-pitched squeaky brakes.
Depending on how and where you drive, brake pads can last anywhere between 25,000 and 60,000 miles. If you've got these cheaper brake pads, you could be subjected to squeaky brakes for a long time.
Buying cheap brake pads is also potentially more costly in the long run because you might not be able to tell when you've reached the wear indicator. If your brake pads wear out, not only do they become less effective which is extremely dangerous, they can also damage the brake discs which are expensive to replace.
When your brake pads need replacing, it's always best to use the ones recommended by the manufacturer.
A car’s braking system consists of many components: discs, pads, callipers, hoses and anti-rattle clips. If any of these parts become loose or weren't tightened sufficiently when fitted, they can vibrate and produce a squeaky sound.
Try to move any of these components - if they're fitted correctly, they shouldn't move. However, if they do move, the offending part will need to be adjusted which is best performed by a trained mechanic.
Alternatively, the part may simply need cleaning or lubrication which should also be completed in a garage.
GLAZED BRAKE PADS AND DISCS
Glazing occurs when brake callipers stick, and the brake pads stay partially applied. As a result, the pad is in constant contact with the brake disc, producing excessive friction and heat.
Overheated brake pads harden and crystallise (also known as glazing). There is much less friction when the brake disc and brake pads crystallise, causing reduced braking power and a high-pitched squeak.
Glazed brakes can often be quickly fixed by a technician who will sand the brake disc and pads to remove the ‘glaze’. They will also investigate the callipers to find the cause of the problem and prevent it from happening again.
If you've explored all our suggestions and your brakes are still squeaking, then we suggest taking your car to your nearest garage to have it looked over by a professional. Use Honest John's Good Garage Guide to find a trusted workshop near you.