Let us first look at the basic parts of a brake system. The pads or shoes are the friction material. When the brakes are applied this is the part that makes contact with the rotor or drum, creating friction and stopping the car. This friction causes the pad or shoe to wear. The pads are moved by hydraulic pressure, created in the master cylinder, pushing brake fluid through the brake lines and pushing out a hydraulic piston attached to the pad or shoe. In a disc brake system this cylinder is found in the caliper. In a system with drum brakes it is found in the wheel cylinder. While many cars today are equipped with disc brakes on all four wheels, many still use drum brakes on the rear. Since the vehicles weight is moving forward when the brakes are applied the front brake pads generally wear faster than the rear. When the brake pads or shoes are worn to a point where they need replacement you may hear a squealing or grinding noise.
When performing a simple brake job the pads or shoes should be replaced accordingly and the rotors or drums resurfaced. Resurfacing these parts means that they are bolted onto a lathe which will cut a very small amount of metal from their face, creating a smooth clean surface. Not resurfacing these parts can result in brake squeal, pulsation and premature pad wear. Before resurfacing the rotors or drums they should be measured to ensure that they are still within manufacturer specification. If not they should be replaced. Rotors or drums which are too thin cause a lot of heat build up in the brakes which can cause brake "fade", meaning that the brakes will not stop the vehicle as quickly as they should. Other brake components should also be inspected, such as the wheel cylinders, brake hoses, calipers and master cylinder. Any fluid leak from these parts could cause brake failure.
Go To Page: 1 2
