It's fairly common to find that the front brake rotors are warped. Likely the rear brakes are out of adjustment and not working properly forcing your front brakes to do the majority of the stopping work. This scinerio will cause the front rotors to overheat and warp, or go out-of-round. If the rotor is out-of-round you will get a pulsing or vibration when you step on the brake pedal.
"How do my brakes work?" The customer asked.
The modern automotive brake system has been refined for over 100 years and has become extremely dependable and efficient.
The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder. Other systems that are connected with the brake system include the parking brakes, power brake booster and the anti-lock system.
When you step on the brake pedal, you are actually pushing against a plunger in the master cylinder, which
forces hydraulic oil (brake fluid) through a series of tubes and hoses to the braking unit at each wheel. Since hydraulic fluid (or any fluid for that matter) cannot be compressed, pushing fluid through a pipe is just like pushing a steel bar through a pipe. Unlike a steel bar, however, fluid can be directed through many twists and turns on its way to its destination, arriving with the exact same motion and pressure that it started with.
Also, it is very important that the fluid is clean and that there is no moisture in it. Dirty or contaminated brake fluid can also cause braking problems. Just removing the cap on the brake fluid resivour to check the fluid level can allow moisture and other containments into your braking system.
If contamination is suspected the brake system must be bled and flushed. There are "bleeder screws" at each wheel cylinder and caliper for this purpose.
Your vehicles braking system is a very important part of your overall vehicle safety package which includes tires, shocks, struts and wheel bearings as well as all of the hardware that goes with these systems. It is important to ensure that your vehicles brakes and braking systems are inspected and maintained at regular intervals.