1. Brake Pads
These babies are designed to clamp on to the discs (rotors) when applied to slow down/stop the vehicle. For those not familiar with the part on a car think back to your childhood bicycle and the front lever brakes. When you squeeze your hand the brakes clamped shut on the front wheel, and rubber pads gripped the wheel to slow you down. Brake pads are the little rubber bits essentially, except on cars they are made of high tech heat bearing material. As high tech as they are, over time they will become worn down though use. Most modern vehicles will have a wear indicator built into the brake calliper that squeals when the pad is wearing out. If you hear a high pitched sound emanating from your wheels it could be a sign that you are due for brakes. Should you wait for this sound before you check? Probably not. Not all vehicles will have this system functioning. The best aspect of regularly having your vehicle serviced by a reputable technician is that they will check your brake wear every visit and let you know when you may be nearing a new set of pads.
2. Brake Rotors (discs)
These are the round shiny discs that the brake callipers and pads grip onto to stop the vehicle. There are 3 main factors that will lead to their replacement: wear; gouging; warping.
Wear is just that, through prolonged use the material of the rotor is worn away and becomes thinner. Technicians will check for a lip and also measure the rotors to establish whether they have become undersized.
Gouging is generally caused by a rock or other foreign material becoming lodged between the calliper and the rotor. This causes a large circular grove around the rotor and can warrant the need for replacement.
Warping is where the rotor will develop a wave. This becomes apparent to the driver as vibrations when applying the brakes - particularly when they are applied on a long steep hill. The warping becomes more noticeable as the rotors heat up. Sometimes replacing the standard rotors with slotted rotors can help.
3. Brake Fluid
Brake fluid is capable of handling extremely high temperatures without boiling - essential to the function of the braking system as it will retain its liquid form without vaporising. Brake fluid must also maintain low compressibility, otherwise your foot will have to travel a long way before the fluid is compressed enough to affect the brakes. The problem with brake fluid is that it is hygroscopic, meaning that it likes to absorb water. Once water becomes part of the braking system it leads to a lower boiling point, higher compressibility (soft pedal) and corrosion.
As part of your service, a qualified technician will check the moisture content of your braking fluid. By maintaining accurate service history your technician will also flush and replace your brake fluid at scheduled intervals to ensure that fluid is fresh and able to do its job properly.