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Know Your Car: How to Check Your Brakes

If you can't "stop," you shouldn't "go." Here's how to check your brakes.

As complicated as modern vehicles may be, there are still a number of basic things that you can do to make sure that your ride is running properly, including checking and adjusting fluids. In addition to knowing how to check your brakes in the garage, you should also be able to ensure that your car stops properly.

Performing a Systems Check

  • Brake Fluid ReservoirBrake fluid level: Locate the brake fluid reservoir. You may have a remote filler located away from the brake master cylinder, or it may be directly on top of the master cylinder. When in doubt refer to your vehicle owner’s manual. With your car on a level surface, the brake fluid level should fall between the lines marked “min” and “max.” If you need to add brake fluid, only use the recommended fluid from a sealed container and follow the correct procedure, all of which can be found in your owner’s manual.
  • Brake fluid condition: Brake fluid breaks down over time as it absorbs water and is subjected to heat. This can lead to fluid oxidation, which can wear out the hydraulic system. New brake fluid is a golden color, which you can see through a plastic reservoir or if you pull the cap off a metal reservoir. If it’s black, it’s time for replacement. There are also brake fluid test strips on the market that check for fluid oxidation. Just dip one of the strips into the brake fluid and compare it to the chart found on the package.
  • Brake warning light: The brake warning light may come on for a variety of reasons, including activation of the parking brake, low brake fluid level, unbalanced hydraulic fluid flow, low brake pad friction material thickness or some other fault in the system. Under no circumstances should you ignore the brake warning light. Find a safe place to park the vehicle and assess the situation. Start with the easy steps and work towards more involved components. Verify that the parking brake is off, then check the brake fluid level. If those two items are okay then you may need a more thorough diagnostic from your local NAPA AutoCare.

Performing an Operational Check

Pay attention to what happens when you step on the brake pedal when you’re driving, as this can indicate the overall health of your brake. The key to keeping on top of brake maintenance is being observant as to how your brakes feel when you’re using them. Here are a few things to watch out for when you are using your brakes:

  • A completely destroyed brake rotor.Abnormal noises: You should hear almost nothing when slowing down and coming to a stop. When you depress the brake pedal, any squealing, scraping or rubbing noises that result are a sure sign that there is something wrong with your brakes. Clicking or clunking sounds could be indicative of abnormally loose brake or suspension parts. Abnormal noises could be caused by something as simple as a stone tossed up into the brakes or as serious as a loose bolt or broken pad. If you hear an abnormal brake noise don’t put off checking it. Not only can brake performance be drastically reduced but the potential repair cost can skyrocket if components start to damage each other.
  • Pulling left or right: If the vehicle pulls to one side when you depress the brake pedal, you may have a hydraulic or mechanical problem on your hands. For instance, if the vehicle pulls to the right on braking, one of the driver-side brakes could be at fault, perhaps due to air in the system or a seized brake caliper slider or piston. Uneven brake pad wear, which can be diagnosed by comparing inboard and outboard or left and right pads, may also indicate faulty breaks. Uneven braking can make for unpredictable steering and make driving in rainy or snowy conditions even more hazardous.
  • Pedal feel: When you step on the brake pedal, it should feel progressively firmer the harder you step on it. If you step on the pedal and it feels light through part of its travel with instances of sudden heaviness, there may be air in the system or a mechanical fault, such as a seized caliper slider. For cars with rear drum brakes, it may be time for a rear brake adjustment.

Performing a Physical Check

Inspection of the brake system components themselves requires a little more effort and tools but can yield a lot of information. You will need a flashlight and a way to safely raise the vehicle off the ground plus remove the wheels. If using a jack always use jacks stands, never climb under a vehicle solely supported by a jack. Once the wheels are removed and the vehicle safely supported you can begin the inspection.

  • Brake lines and hoses: Put on a pair of safely glasses and grab the flashlight. Starting at the brake master cylinder trace each brake line to its end at the wheels. Look for any signs of corrosion or leaking. A leaking hard brake line must be fixed immediately. Replace any rubber brake lines that show signs of swelling or leaking.
  • Brake pads and shoes: Most brake calipers have an opening where the brake pad thickness can be observed. Measure the thickness of each pad. While each vehicle has a specific minimum pad thickness, a good rule of thumb is to replace them once they are 1/8″ thick or less. For drum brakes there may be an inspection hole to measure the brake shoe thickness. If not you will need to remove the brake drum for an accurate measurement. Minimum brake shoe thickness can vary greatly from vehicle to vehicle, so it is best to consult a repair manual for proper specifications.

Since brakes are one of the most important safety systems, knowing how to check your brakes can go a long way toward keeping you safe as well as improving the longevity of your car.

Check out all the brake system products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on how to check your brakes, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Image courtesy of Flickr.


Benjamin Jerew View All

Ben has been taking things apart since he was 5, and putting them back together again since he was 8. After dabbling in DIY repairs at home and on the farm, he found his calling in the CGCC Automobile Repair program. After he held his ASE CMAT for 10 years, Ben decided he needed a change. Now, he writes on automotive topics across the web and around the world, including new automotive technology, transportation legislation, emissions, fuel economy and auto repair.

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