You may not think about this very often, but the brakes on your vehicle are a feature that should always be in perfect working order. It is important to regularly check the condition of your brakes. How do you know when you need new brakes?
Listen and watch
There are two ways to check the condition of your disc brakes: by looking and listening. First, check for wear by examining your brake pads through the gaps between the spokes of the wheel. The outer bearing will be pressed against a metal rotor. As a rule, there should be at least a quarter inch of pad. If you see less than a quarter inch of pad, you may want to have your brake pads inspected or replaced. Have you ever heard a high-pitched scream when you braked? It is a small metal shim, called an indicator, that warns you that you must replace your brake pads. You must be aware of this sound (which is loud enough to be heard when the windows are raised, but not loud enough to be heard with the radio on or the air conditioning on). If you hear it regularly, make an appointment with your mechanic as soon as possible.
Reduced brake reactivity
If your brakes do not react as they should or if the pedal depresses towards the ground, it could indicate a leak in the braking system. This can be an air leak (in the brake hose) or a brake fluid leak. One indication of a brake fluid leak is the presence of a small pool of fluid when the car is parked. Brake fluid looks like fresh engine oil, but with a less viscous texture.
A grinding or rumbling noise
If you hear as a grinding sound, this loud metallic sound means that you have completely worn out the pads. The rumbling noise is caused by the friction of the two metal parts (the disc and the caliper). This can scratch or even damage your rotors and create an uneven surface. If this happens, don't be surprised if your mechanic tells you that the rotors must be "turned" (a process that levels the surface of the rotor) or even replaced. To avoid these problems, the solution is to check the condition of your brakes on a regular basis.