Audi recommends a brake inspection every 15,000 miles, about a year’s worth of driving. It’s a cheap way to head off brake problems. Brakes wear as they do the job of slowing you down. Here’s the extended version of how brakes work and what to look for with a developing problem. When you step on the brake, you push a piston in the master cylinder to compress the brake fluid. The pressure you create is transferred to the other brake components through brake lines to each wheel. Like all mechanical devices, the master cylinder can wear out. If the pedal goes to the floor or feels soft when you brake, that can indicate that a new master cylinder is needed. Brake fluid should be clear; if it looks dirty, master cylinder seals may have broken down and let pressure escape. A brake fluid leak can also mean worn seals. A brake light on the instrument panel may warn of a bad master cylinder. Modern cars all have power brakes. The brake booster must use vacuum pressure from the engine to give you the brake boost you want. If you notice one of the following symptoms, you may need a new brake booster:
-Firm brake pedal
-Longer stopping distance than usual
-When you brake, the engine stalls
Besides transferring pressure from the master cylinder to the brake pads, brake fluid absorbs the heat braking action generates. Brake fluid also collects water from the air and needs to be drained and filled every two years to head off the rust water can cause. If you notice a spongy brake pedal, your brake fluid may leak and cause bleeding pressure. If your braking action isn’t as good as you are used to, the brake fluid may be contaminated, or air may have leaked into the system, requiring bleeding. Your Audi has a warning light that notifies you that the brake fluid level has dropped too low for safety. Metal and rubber hoses connect the master cylinder to the calipers. These hoses are a source of leaks which can also cause a soft brake pedal. The calipers hold the brake pads next to the rotors. When you press the brake pedal, the calipers guide the brake pads to press against the brake rotors. The pads cause friction, which converts your motion energy to heat energy. The calipers are designed to handle this heat but will deteriorate over time. Caliper seals can leak, and road dirt can cause caliper pistons to seize. If this happens, the wheel with the seized caliper will have no braking action, and the car will pull away from that side under braking. If the caliper pistons lock up against the rotors, you will drive around with partial braking action, causing increased pad wear and poor fuel mileage.
Brake pads wear as they do the job of slowing the vehicle. Brakes function by pressing pads against rotors; disk-shaped components bolted to your wheels. Brakes wear differently based on highway miles vs. stop-and-go, hill driving, and how hard you use your brakes. Because of this, frequent inspections are a must. Our technicians inspect your Audi brakes and check for leaks and dirt buildup. The following symptoms may accompany pad and rotor problems:
- Pulsation or vibrating in the steering wheel or brake pedal
- Squealing or screeching when braking
- Pulling to one side while braking
- Longer stopping distance
- Burning odor
- Grinding noise when the brakes are applied
- You may notice grooves on the rotor
- Should you encounter these, bring your Audi in for service immediately.
