COMMON BRAKE PROBLEMS AND MAINTENANCEDecember 1, 2010 | in Defensive Driving Tips
Your brakes are easily one of the most important components of your car. Having well-maintained and effective brakes will go a long way towards keeping you safe on the road! Few things are more terrifying than jamming on the brakes in an emergency and finding they don’t work. Before reading further, it may be helpful to check out a previous entry on how brakes work. This will help you to understand some of the problems discussed here.
Should you experience brake failure, there are a few things you can do to slow down your car and minimize potential damage; check out these tips. However, this situation is best avoided altogether!
First, practice good driving techniques to avoid putting excess wear on your brakes. Regularly braking hard, “slamming on the brakes”, puts a great deal of strain on your brakes. Driving in stop-and-go traffic also exacerbates brake wear; if possible, try to arrange your schedule so as to avoid the worst of rush hour. While driving, don’t “ride” the brake pedal or let your foot rest on it. Also, coasting to slow down before braking can help to save your brakes. Try to plan ahead; slow down if you see cars braking ahead. Look down the road a ways to spot other hazards, stop signs, and red lights that may be coming up in your path. Also avoid carrying excess weight in your car, as this will put extra strain on your brakes. Note that several of these strategies will also help you to save gas! Finally, there are different grades of brake shoes and brake pads. While the lower grade pads are cheaper initially, they will wear out faster and often don’t perform as well. Purchasing the higher grade pads and shoes will be more cost-effective in the long run and will reduce wear on the other components of your brake system as well.
Next, pay careful attention to the feel of your brakes when braking and the sound they make. Unusual noises and feelings can be symptoms of brake problems. Here are some of the most common problems and their causes:
Brake warning light comes on: This most likely indicates that there is a leak in the system. Don’t drive until you have had the system checked out, and any leaks have been repaired.
Brake pedal “rests” at a lower position: This is usually caused by drum brake adjusters not working properly. If the adjusters are rusty or they stick, they won’t advance properly. In addition to having the brakes readjusted, you will need to have the adjusters cleaned or replaced. This could also indicate that the brake pads or shoes need to be replaced or that there is a leak in the system.
“Spongy” brake pedal: If your brakes are “soft”, i.e. the pedal doesn’t offer as much resistance when you push it, then there is likely air in hydraulic system somewhere. Your mechanic will need to “bleed” brake lines, i.e. drain and replace the oil.
Need to push pedal too far in: This could be due to a variety of problem: worn brake pads or shoes, poorly adjusted drum brakes, or air in the lines. You can pump the pedal several times to compensate for this, but you will still need to get your brakes checked as soon as possible.
Pedal pulses or vibrates when you brake: This occurs when the rotors on the disc brakes, which should be flat, are worn unevenly. As a result, they don’t make contact evenly with the pads, which then causes vibrations. The rotors need to be resurfaced or, if the problem is severe, replaced.
A scraping noise: This occurs when there is metal to metal contact in the brakes, which means that you have worn entirely through the brake pads or shoes. A brake servicing is long overdue! Driving with shoes or pads this worn can seriously damage your brakes, forcing you to replace more expensive parts in your brakes.
A squealing noise: This can be caused by vibrations between the brake pads and rotor or caliper. This may be unavoidable on some older brakes which use semi-metallic compounds in the pads. Replacing the brake pads with newer ones can help. There are a few other strategies your mechanic can use to minimize this noise. However, this could also be a more serious problem, such as worn brake pads or a missing gasket, so do get your brakes checked soon.
A jerky, “slip-and-grab” feeling: It’s likely that brake oil or another substance has leaked onto to the brake mechanism. Contaminated pads will need to be replaced and, of course, the source of the contamination has to be identified and stopped.
Pedal sinks to the floor: This occurs when pressure isn’t being maintained in the hydraulic system. This is likely a leak or a worn-out master cylinder. Don’t drive in this situation! Instead, have your car towed and fixed immediately.
Brakes don’t release properly: There are several potential causes: the springs in the drum brake are not working properly; the floating caliper in the disc brakes isn’t adjusted correctly; the emergency brake cable or mechanism is broken; or the adjuster mechanism in drum brakes has extended too far.
Car swerves to one side when brakes are applied: This means that braking power isn’t evenly distributed between the front brakes. The car will “draw” to the side with the stronger brake, as the opposite wheel now has greater driving power. It’s likely that a leak, broken piston, stuck caliper, or other mechanical failure has occurred in one of the brakes. This can also be caused, however, by different brands of brake pads being used on the two front brakes, as different makes of pad and compounds have different braking properties.
Brakes are hard or difficult to use: Usually this means that the vacuum assist isn’t working properly, forcing you to put a lot more power into the system. The booster itself could be leaky or defective, or the check valve could be failing. You can test the check valve by running the engine for a few minutes (building vacuum) and then turning off car. If you don’t have power assist after a few minutes, the check valve is broken. To test the vacuum booster itself, turn off the engine. Pump the brake pedal a few times to “bleed” all remaining vacuum from the booster. Then, restart the engine and let it run for a couple of minutes. This should build vacuum in the booster again. Now, try your brakes. If there’s no power assist, this means that the vacuum booster is broken.
ABS Warning light comes on: This means that the computer has detected a problem in this system and turned it off. While this isn’t going to put you in immediate danger, it’s still better to have this system checked sooner rather than later.
Brakes lock: This is likely caused by a damaged brake pad or shoe. Have your car towed immediately.
In addition to listening for problems like these, you should also check your brake system periodically in order to stop problems before they happen. First, check the level of brake fluid in the reservoir often. If necessary, top up with fluid as needed; if the level of fluid seems to be sinking quickly, have your mechanic check for a leak.
Have your brake pads checked regularly and changed as needed. How often you will need to do this depends a lot on your driving habits and the car you drive. In general, brake shoes will need to be replaced after four rotations of brake pads.
Finally, take a moment from time to time to check that your brake lights are working.
You should have a thorough “brake job” done either when the pads are worn down or if you notice any of the symptoms above. Your mechanic will carry out a variety of routine maintenance tasks, including replacing the front pads, resurfacing the rotors, replacing the shoes (if needed), resurfacing the brake drums, bleeding the brake lines, checking for leaks, and checking and adjusting the parking brake.
More comprehensive maintenance will also include new hardware for drums, springs in particular age with exposure to heat and should be replaced, and the of rebuilding wheel cylinders and calipers.
To read more on a broad range of subjects from “How To Change A Tire” to “How To Jumpstart Your Car”, visit DefensiveDriving.com’s Safe Driver Resources website!
Check out these sites for more information about online defensive driving courses in Texas, Florida, California, and New Jersey.← No Refusal Traffic Stops | C’Mon Man! →