Unless your car never leaves the driveway, you will eventually need to have your brakes serviced. Brake repair is often very affordable, but can become expensive if a problem is left too long untreated. The most common brake system today consists of disc brakes in the front and rear, connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder.

Master Cylinder
Master cylinders have become very reliable and rarely malfunction. The most common problem that they experience is an internal leak. This will cause the brake pedal to slowly sink to the floor when your foot applies steady pressure. Letting go of the pedal and immediately stepping on it again brings the pedal back to normal height. If the master cylinder fails, the brake warning light on the dash will light, alerting you to the problem. Brake repair for a faulty master cylinder will cost between $150 and $250, parts and labor included.

Brake Fluid
The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent reservoir so that you can see the level without opening the cover. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Brake fluid should be clear or slightly yellow. If it is dark and dirty, it will need to be flushed and replaced. This should cost less than $100.

Brake Lines
The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. If any of these conduits fail, they must be replaced. This type of brake repair often involves significant labor, so whereas the parts might only cost $40, the total bill could come to $200.

Brake Pads
The main components of a disc brake are the brake pads, the rotor, and the caliper. Brake pads wear out with use and must be replaced periodically. If the lining wears down to the metal brake shoe you will have a metal-to-metal condition where the shoe rubs directly against the rotor causing severe damage and loss of braking efficiency. Replacing the pads on the two front wheels can cost less than $100, parts and labor included, and will save you from more costly brake repair involving the rotors.

Rotors
The disc rotor has a highly machined surface where the brake pads contact it. Just as the brake pads wear out over time, the rotor also undergoes some wear, usually in the form of ridges and groves where the brake pad rubs against it. If worn-out break pads damage the rotors, you will likely need to replace both pads and rotors. This can cost anywhere from $250 to $600, depending on make and model. It is occasionally possible to machine and resurface damaged rotors. This can bring the cost down, but it comes with the risk that the thinner rotors will warp in the high heat caused by friction between pad and disc.

Calipers
Brake repair involving the calipers can be expensive. The caliper is what pinches the brake pads onto the disc when you step on the brake pedal. If the calipers lock up, the brake pad will wear down to metal and then damage the rotor. If, on the other hand, the caliper pistons start to leak hydraulic fluid, they won't be able to press the pads against the rotor, and the brakes will fail. Calipers can cost $200-$400 apiece, so a brake repair for both front wheels can cost as much as $1,000 with labor.