As your car ages and the forces of friction and heat take their toll on brake components, your braking system will gradually begin to lose some of its effectiveness. To keep your vehicle safe, you need to keep your brakes properly serviced, and the first step in that process is a brake inspection. The main elements of the brake system should be checked about every 10,000 miles or so. How frequently you check may depend on a number of factors such as the age of your vehicle, the type of braking system, the terrain where you live and the manner in which you drive. Someone who lives in a hilly area like San Francisco will wear through brakes more frequently than someone living in Santa Fe, for example, because of constant braking to slow or remain stationary on hills. Likewise, people who tend to ride the brake pedal will cause their brakes to wear out prematurely. Mileage that you put on your car driving in city traffic -- with all of its stops and starts -- is harder on brakes than highway mileage. On average, it's a good idea to check your brakes at least once a year, but it certainly won't hurt to do it more frequently. While Driving Be aware of how the braking system feels when you're driving. If the brake pedal loses its firmness or goes almost to the floor before engaging, the system should be checked. It could mean that the brake-fluid level has gotten low or is leaking. Vibration or shaking in the pedal or steering wheel may indicate that rotors are in need of replacement or resurfacing. Also, listen for signs that the brakes are worn. A squealing sound indicates that the pads are wearing thin. (Some pads, in fact, have a squeal pin specifically to let the driver know when the pads are wearing down.) The sound of grinding or metal-on-metal can be a sign of even more serious problems. Letting that condition continue is likely to ensure that you'll be needing to replace your rotors as well as your brake pads. Under the Hood Check the level of the brake fluid in the master-cylinder reservoir. Most reservoirs are translucent, so checking the level is easy and should be done at least once a month. If the level is slightly low, top it off by pouring fluid into the reservoir. Brake fluid needing to be topped off frequently may indicate that there is a leak in the system, possibly in one of the brake lines. - Tip: Before adding brake fluid to the reservoir, wipe the top and lip of the bottle clean to prevent contaminants from entering the system. Also, avoid spilling brake fluid on painted surfaces, since it will damage automotive paint.
It's a good idea occasionally to remove the lid and get a close look at the fluid. Fresh fluid is clear or translucent. Fluid that is old and beginning to wear out takes on a dark, dirty appearance (figure A) because of contamination by brake dust, dirt, moisture, etc. If the brake fluid appears dark, it's time to have it replaced.With the Car on a Lift Check the brake lines underneath the vehicle. Both the flexible-hose lines and the metal lines (figure B) should be free of any signs of leaks. The metal lines run the length of the vehicle, so check them all along their span. Also check the rubber lines that deliver brake fluid to the brake calipers (figure C). Make sure that they are flexible, that there are no cracks, kinks or leaks, and that they are clear of any moving parts or heat-producing elements such as the exhaust system. Check the parking-brake cable to make certain that it is clean, undamaged and able to operate properly. With the Tires Removed On disc brakes, inspect the condition of the rotor, making certain that it is not damaged or showing early signs of wear. Gouges or scratches to the rotor (figure D) may indicate that contaminants (e.g., gravel or sand) have lodged between the pad and the rotor and caused damage. Heavy scratches or scarring should be repaired by having the rotor resurfaced -- or "turned"-- by a brake specialist. Check condition and overall thickness of the brake pads inside the calipers. For drum brakes (figure E) carefully remove the drum so that you can examine the inside. It's advisable to wear a particle mask during this procedure to avoid breathing brake dust (figure F). Inspect the interior of the drum and look for damage or glazing to the surface. Other trouble signs to check for when inspecting the brakes include excessive brake dust; a warped drum or disc; a defective or damaged wheel cylinder or caliper; and grease or fluid in the area of the pads, shoes, drum or disc.
RESOURCES :
Auto Repair for Dummies
Author: Deanna Sclar
ISBN: 0764550896
Automotive Brakes and Antilock Braking Systems
Model: 0314028382
Author: Kalton C. Lahue
(1995)
To order this title from Amazon.com, click here.
Delmar Learning
Brake Handbook
Model: 0895862328
Author: Fred Puhn
(1985)
Order this book from Amazon.com.
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