When you apply the brakes in your car, a complex system of mechanical components work together to bring you to a stop. The fact that it reliably stops your three ton car thousands of times over years of use is an amazing thing. However, everything mechanical wears out over time and your brakes are no exception to this. Here are six signs that indicate when your brakes need repair or replacement.

1. You Hear a Loud High Pitched Squeal

Brake pads contain within them a piece of metal called an indicator. When your pads wear down too much, the indicator becomes exposed. It then rubs against the rotor and produces a very loud, disturbing and unmistakable squealing sound. This means your brake pads require changing.

2. The Brake Warning Light Turns On

This sign is obvious, but sometimes the light doesn't always stay on. Many drivers breathe a sigh of relief when the light turns off and pretend the problem went away. Whether the light is constant or intermittent, get your brakes checked.

3. The Brake Pedal Goes to the Floor

This is a serious condition and could mean that you have a bad master cylinder. This device converts the pressure you exert on the pedal into hydraulic pressure. A symptom of a malfunctioning master cylinder is the brake pedal going down farther than usual and even bottoming out on the floor.

4. Your Brakes Pulsate

Rotors sometimes develop high spots that produce a pulsating effect while braking. When this occurs, your rotors will either require replacement or possibly "turning," which is a method of smoothing the rotor by shaving metal off.

5. Your Brake Fluid Looks Milky

Sometimes water condensation gets into the brake fluid and gives it a milky color. Change the fluid when this happens to avoid damaging the master cylinder and the wheel cylinders. You can easily check the brake fluid by looking under the hood of your car. The owner's manual will tell you how to locate the brake fluid reservoir.

6. Your Brake Lines are Rusty

Brake failures on the road are often caused by rusted lines that fail and spill out brake fluid. Brake lines have a thin protective layer that wears down from rocks and other debris, which exposes the steel underneath to rusting. A small amount of rusting is okay, but heavy flaking or bubbling rust is not.

Avoid costly repairs and possible brake failure by recognizing the above problem signs. If your brakes feel weak and require more stopping distance than usual, get them checked.