How do rear brake discs work?
The brake disc is a metal plate mounted on the wheel hub that is clamped between 2 rear brake pads when braking is applied; this causes friction and slows the vehicle down.
How often should brake discs need replacing?
As a rough guide, your** brake discs** should last between 50k and 70k miles, but there are many variables that could affect this, including driver behaviour, the weight you carry and the speed you travel.
The law, vehicle regulations and your MOT
Nearly 20% of MOT failures are caused by faulty brakes. Incorrect brake function, damaged or excessively worn discs or pads are considered unsafe for your vehicle performance and will cause your car to fail its MOT.
What causes rear brake discs to stop working correctly?
Rear brake discs wear out over time from continual use. The friction applied by the brake pads, and the intense heat generated, will eventually deform the disc, causing it to become thinner and less effective when performing its job.
Extended use can also cause rear brake discs to crack, rendering them ineffective. Scars and rust on the disc can be caused by debris thrown from the road and poor weather conditions; this is also effective in reducing the operation of your brake discs.
Symptoms of malfunctioning rear brakes
Braking causes unusual noises
Loud screeching or grinding noises from your brakes is an indication that there is a problem with either your brake discs or pads.
When your car pulls to one side under braking
If only one brake is working correctly, it can cause your car to pull in the direction of the functioning brake.
The car vibrates under braking
Your brake pads or discs could be warped if the pedal vibrates when you press down on it.
The brake disc shows signs of damage
Look through the wheel for a visual check—if the disc’s surface isn’t smooth, or it displays cracks, grooves, spots or a blue colourisation, then the disc is quite likely damaged.
Your brake warning light on the dashboard is illuminated
If any of your dashboard warning lights are illuminated, the sensor that detects problems or worn out parts and components has identified an issue and activated the system.