We all know that pushing down on the brake pedal slows a car to a stop but how does this happen? Clearly, our leg power alone is not strong enough to stop something as big as a fast moving car, so something must be happening to take the small movement of our foot to generate enough force to stop it.
Car brake systems work on three main principles:
If you look under your bonnet you will see a reservoir for the brake fluids. If this drops too low it could mean that you have a leak in the hydraulic system. The basic idea behind any hydraulic system is very simple – a force applied at one point is transmitted to another point using an incompressible fluid. Most brake systems also multiply the hydraulic force using servo units.
You press the pedal (leverage), the hydraulic system transmits and multiplies that force to the braking units on the wheels themselves, and friction takes over! This is where much of the real work of your braking system is done. The discs and drums apply a resisting frictional force to the spinning wheels to slow them down, hopefully bringing the car to a smooth stop.
There are some tell-tale signs that may indicate that you need to get your brakes looked at.
Reduced responsiveness or fading. If your brakes are not as responsive as they should be or if the pedal feels spongy or sinks toward the floor, this could be an indication of a leak in the braking system. One tell tale sign of a brake fluid leak is the presence of a small puddle of fluid when the car is parked. Brake fluid looks similar to fresh motor oil, but with a less slimy texture.
Pulling. If your vehicle “pulls” to one side when you are braking, it may be a sign that the brake linings are wearing unevenly or that there is foreign matter in the brake fluid. Your vehicle may need a brake adjustment or to have the fluid drained and replaced.
Noise from the wheels when you brake. Do you have a high-pitched screeching sound when you apply your brakes? This may well be a sign that the pads are worn and need replacing.
One exception is if your car has been sitting after being exposed to water, such as from rain or from washing it. The moisture can cause a thin layer of rust to develop on the brake units. This is normal. When you first apply the brakes, the pads pressing on the rust-covered rotors may cause a squeal for a few stops until the rust is worn off and then the sound will disappear.
If you have a loud metallic grinding sound it probably means that the pads have been worn down completely, most likely beyond replacement. The grinding or growling noise is caused by the two pieces of metal (the disc and the caliper) rubbing together and is a very bad sign! It usually means that the brake units will have to be replaced completely.
Vibration. A vibration or pulsating brake pedal is often a symptom of warped rotors. The vibration can feel similar to the feedback in the brake pedal during a panic stop in a vehicle equipped with anti-lock (ABS) brakes.
TOWER GARAGE TIP
Maintaining your vehicle’s braking system is something that must not be overlooked. As with so much with cars, keeping your brakes properly calibrated and in good working order can prevent costly repairs down the line, as well as contributing to everyone’s safety when you are driving.
If you are worried about any aspects of your car’s braking then contact us now for a professional assessment. This is one area that is simply too important to be left to chance!