First off, I want to make one thing clear…sometimes brakes make noise. If you expect absolute silence from your brakes all the time you’re going to be disappointed. Don’t worry though, squeaky brakes stop cars just as well as when they’re silent. So why is it that brakes squeak sometimes?
Types Of Brakes
There are two types of brakes:
- Disc brakes involve a disk/rotor where pads clamp down on it to slow the car down. These are generally found on the front wheels of cars and in some cases they’ll be on the rear wheels as well.
- Drum brakes involve a hollow drum where a curved “shoe” presses against the drum to bring the car to a stop. This type of brake is usually found on the rear wheels of cars.
Four Common Reason For Brake Squeaks
The following 3 types of squeaks happen with disc brakes only:
- Morning squeaks due to the build up of moisture either due to rain/morning dew.
- The brake wear indicator touching the disc to indicate the brake pads are getting thin.
- Brake pads with a high metal content. High metal content is usually only found in cheap brake pads.
The last type of squeak only occurs with drum brakes:
- Squeaks due to the shoe-to-backing-plate contact points needing lubrication
Fixing Squeaky Brakes
Morning squeaks occur because of moisture causing a thin layer of rust to form on the disc/rotor. As you brake the pads push against the disk and the rust then collects on the leading edge of the pads. Once embedded in the edges of the brake pad, the brakes begin squeaking. The only way to prevent this is to store your car in a garage or somewhere with little to no moisture in the air.
Brake Wear Indicator
The brake wear indicators are small metal tabs made of hardened steel which are designed to hit the disk/rotor before the brake pad wears out completely. This helps notify the driver that the brake pads are getting dangerously thin. The obvious and only solution here is to replace the brake pads.
High Metal Content Brakes
Brake pads normally contain traces of metal bits. The cheaper brake pads use higher amounts of metal in their pads though which will cause a high pitched squeak. And since brake pads last a good 20 000km – 30 000km, using cheap brake pads could have you listening to squeaky brakes for a long time. The best solution here is to spend the few extra bucks on brake pads with less metal and more organic material such as resin, rubber, Kevlar or fiber.
Unlubricated Drum Brakes
If you start hearing squeaking coming from your rear brakes it’s likely because the shoe-to-backing-plate contact points need lubricating. When these contact points lose lubrication, they begin to rust and this causes the shoes to scrape against the backing plate, which in turn makes a rthymic sound when braking. The solution to this is to apply lubrication to the contact points. This can be done with a lubricant called Moly Paste 60. You can find it on amazon or your nearest motor spares store. If you can’t find Moly Paste 60, you can use a high temperature anti-seize compound.