The braking system is one of the most important safety components on a vehicle. Therefore, it’s vitally important to make sure you’re aware of how to recognise any issues.
It’s always easier to spot a problem if you know how something works, so let’s take a quick look at the braking system and how it all fits together.
There are several different components that all work together to make a vehicle stop or slow down when travelling at speed. The vehicle braking system includes master cylinder, servo, brake calipers, brake fluid, brake pipes, brake cylinders, discs, drums, pads and shoes. These components are all linked by the brake hoses and pipes.
When you push down on the brake pedal, the servo boosts the force applied to the master cylinder, which fills with brake fluid. The cylinder is then pressurised by a series of pipes and hoses that activate the pistons in the brake caliper. This forces friction from the pads or shoes onto the brake disc or brake drums, which then stops your car.
Vibration felt through the steering wheel could be an indication of warped discs. This would occur if your brakes have been overworked recently – for example, if you’ve had to stop frequently while towing something heavy. If you feel a vibration at higher speeds it could simply be a sign that your wheels need to be balanced.
If you’re hearing this, the brake pads could be worn to an excessive level as it is likely to be the sound of the metal disc and low brake pad material conflicting and causing abnormal brake noise.
If your vehicle feels as though it is pulling to one side when braking it could mean that the brake discs are wearing unevenly, that your rotors are contaminated from a fluid leak, or that you have a malfunctioning caliper. However, pulling can also simply be a sign of uneven tread wear or overinflated or underinflated tyres.
If the pedal grabs too soon, you could have uneven brake discs, seized pistons, misaligned calipers or contaminated brake pads.
This would be noticeable if your brake pedal goes almost to the floor before engaging the brakes. While this could indicate worn brake pads, it may also be a sign of a problem with the hydraulic system (for example, your brake fluid could be leaking). The brake fluid could also be contaminated with water or become overheated and ineffective. This is why most manufacturers will recommend that brake fluid be replaced every two years or at a set mileage.
You’ll notice if you have a hard pedal when you need to apply extreme pressure for the brakes to engage. The most common cause of this is the servo. A faulty servo won’t provide vacuum assistance when you press the pedal, meaning you have to press harder. Another cause could be a vacuum hose component leak, again causing the vacuum assist to weaken. The valve, which allows air to exit the servo (but not to enter it) can also malfunction or break. And finally, it could simply be that the incorrectly sized parts have been fitted.
An illuminated brake light on your dashboard is likely to indicate that your brakes aren’t properly released, that your brake fluid is low or your ABS is having problems (if your ABS light comes on at the same time).
Many of these problems with a vehicle’s braking system are potentially serious safety issues. If you notice any of these signs, you should take your car to your local service centre where a fully trained and qualified technician will be able to investigate and quote you for the best fix or replacement of the correct failed parts.