How your car works - Shock Absorbers & Brakes

These Are Vitally Important Safety Components
Disc Brake and Shock Absorber assembly, showing suspension parts: Although it's something that many of us rarely think of, it is actually these parts that make your car safe and pleasurable to drive, ensuring that it will steer around corners and come to a stop when needed. It is really only when there is a strange noise coming from under your car or your steering and braking behave in a new and unusual way that any concern should arise of there being something wrong. Your brakes and shock absorbers are probably the most important yet unappreciated parts of your car. It is usually just once a year that these parts are inspected for the MOT test or an annual service. The yearly inspection may be sufficient but there is of course a need to monitor your car's handling and stopping at all times. If for any reason your car displays any of the symptoms listed below then have it inspected by your nearest Unipart Car Care Centre as soon as possible.

The Disc and Drum Brakes
There are two types of hydraulic brake systems used on cars. One is the drum type (the brakes are inside a drum) and the other is the disc type (the brakes are on the outside of the disc). Most cars nowadays have discs at the front and drums at the rear. High performance cars can have disc brakes all round. The typical system consists of discs, pads, master cylinder, calipers and hoses. Components such as the master cylinder and calipers are unlikely to go wrong in normal use, but the discs, pads and hoses will need replacing every so often. The other component that must not be forgotten is the hydraulic fluid. This fluid is a very important part of the system and it will need checking frequently for the brakes to work efficiently every time you press the pedal. You will need to check it visually by looking at the level in the reservoir (under the bonnet) and it will need replacing every 1 to 2 years regardless of mileage. If in any doubt as to how to check the fluid level or the brake pad wear then consult your local garage for advice.

The Shock Absorber Assembly
There are several types of shock absorbers used on modern day cars but the most common is the telescopic type filled with gas (there are also air and oil filled types). To help you visualise a way in which a shock absorber works, take a bicycle hand pump and place your thumb over the end that attaches to the tyre valve. If you now gently push down on the handle you will notice that it will only go so far and then it forces itself back up. The shock absorber works in much the same way and this damping action is most noticeable when the car goes over a bump in the road. In reality, this damping action occurs constantly when driving (mostly unnoticed). However, it is when you go over a rough surface or round a bend and the car leans, bounces or knocks too much that you will then become aware of the fact that the shock absorbers are not working as well as they should do. If the car is displaying any of these symptoms, have it inspected immediately by your nearest garage as it may be in a condition that is not safe to use on the road.

Caring for your shock absorbers and brakes
These are some of the warning signs you should look out for:

Brakes

• Juddering through the steering and/or brake pedal
• Brake pedal 'fading' away when applied
• Grinding noises when braking or when moving slowly
• Warning lamps illuminated on the instrument panel (fluid pressure / level, ABS or low brake pad linings)
• Excessive pressure needed on pedal to stop the car

Shock Absorbers

• Bouncing or weaving across the road
• Swaying at speed or when going over large bumps in the road
• Knocking noise (bottoming out) when going over bumps in the road
• Headlamps incorrectly aligned (pointing too high or low)

Other signs:

• Veering across the road in any direction or a particular direction can indicate both shock absorbers and brakes are worn.
• If your car displays any of these symptoms you must take action without delay and go to your local garage for safety checks to be carried out.