After its steering, the brakes are probably the most important of your car’s controls. Sometimes car brakes squeak, squeal or screech depending on your viewpoint and the problem. This can be caused by one of several reasons. It might be quite innocent; it might need professional attention. Read on to find out more.
If the brakes feel different in any way so the car is pulling to one side, the pedal feels soft or braking power is diminished at all, you should seek professional advice.
Metal on metal
To understand the primary cause of brake squeal, it’s important to understand what brake pads are made of. Most brake pads comprise shavings from metals such as copper, brass and steel bonded together with a resin. This makes a durable component that’s needed to help bring a tonne or more of metal, rubber, plastic and human to a halt on a regular basis. However, when they’re cold, the metal components in the pad can squeak when they rub against the metal of the disk. This noise should stop when the pads warm up.
Solution: Frequently this will be an intermittent problem. That’s because the metal fragment squeaking against the brake disc will eventually wear away. Brake squeak can be caused by cheap pads so when they need replacing, use those recommended by your car’s manufacturer.
Rust on the disc
If you park your car overnight and it’s got wet brakes, a light film of rust can build up on the discs. When you brake, the pads wipe this off and it forms a layer on the leading edge of the pads. This then squeaks when it rubs against the disk – again until it’s wiped off.
Stone caught against the disc
This causes a screeching noise when you’re driving along rather than when you press the brakes. It usually happens after you’ve driven over gravel or a loose surface. A stone jumps up and gets caught between the disc and its backing plate.
Solution: You can wait and see if it works its way out. If it doesn’t in a short space of time it’s unlikely to. You have two choices here: you can either take the car to a professional and ask them to dislodge it. With the car on a ramp and the right sort of poking tool it may only take a couple of minutes and they may not charge you.
Alternatively, you can grovel around beneath the car yourself. You may find it a lot easier if you take the wheel off. It’s one of those jobs where the time it takes to remove the offending stone is a fraction of what it takes to jack the car up and remove and replace the wheel.
If you choose either of these DIY fixes, make sure the car isn’t on a slope, the parking brake is applied, the car is in gear and you familiarise yourself with the jacking points. And if there’s any chance you might pull the car off its jack, take it to a pro.
Worn out pads
Most modern cars have a contact on the brake pads that prompts a light on the dashboard to come on when the pads wear down to a certain level. Don’t ignore this light: you will have some grace but not much. Whether your car has a warning light or not, your brake pads should be checked whenever the car is serviced.
A real screeching sound – much louder and more intrusive than a squeak ‑ when you brake and your car is telling you that the pads need replacing. If this becomes a grinding it’s because there is no pad left. Your car is unsafe to drive so pull over and have it recovered to a garage.