Changing the brake pads on your car may seem like a daunting task, but in reality, it is surprisingly simple. If you have the right tools and the right knowledge, the job can be completed in under two hours, and at a substantially lower cost than having a professional do it.
Everyone at one time or another has heard the awful squeak of their brake pad wear indicators while driving. It is usually a high pitched sort of “scraping” noise, similar in some respects to the proverbial “fingers across a blackboard” sound. It can be heard either while pressing on the brake pedal, or when you’re not, it just depends on the vehicle. In either case, that sound usually means the brake pads are worn, and need to be replaced.
To do the job yourself you’ll first need to gather up some tools. It’s probably a wise idea to invest in a quality hydraulic jack. If you do a lot of your own car maintenance, you’re going to have to lift the car up pretty often, and if you use the jack that came with your vehicle, you’ll find it is more time consuming and takes considerably more effort over using a hydraulic one. You will also want to invest in a set of jack stands, to secure the car while it is lifted off the ground.
The next thing you’ll need is a good mechanic’s tool set. For doing brake work you’ll only need the most basic of wrenches and sockets, as well as a ratchet, 3/8ths drive preferably. You’ll also want to make sure you have a flat tipped screwdriver, or a suitable pry bar to remove your hub caps or covers, if present. In some cases you will also need to invest in a unique socket to remove the brake calipers. Many General Motors vehicles (including Buick, Oldsmobile, etc.) have such bolts holding their calipers to the suspension. Ask your auto parts dealer or a professional mechanic if you’re not sure if you will need one. There are other vehicles with special types of bolts as well, so if you are not absolutely sure the bolts are “regular” hex head bolts, it’s always a good idea to ask someone who can give you that information. It’s also advisable to have on hand a large “C” clamp to press the caliper piston back into its bore, usually a 6-inch will suffice. Alternatively, a large pair of slip joint pliers can be used.
While you’re at the auto parts retailer, invest in some shop rags, and, find a can of aerosol brake cleaner. You can spray it on the brake calipers to remove any brake dust that has accumulated, and will make the job a little less “dirty”. You may also want to buy some non medical latex gloves, to protect your hands.
The job itself is fairly straightforward. First, you’ll want to place a chock behind the opposite wheel to the one you will be lifting. For instance, if you are going to start with the driver’s-side front brakes, then place the chock behind the passenger side rear wheel. “Real” chocks are available to purchase, but a large stone or old cinder block will serve the purpose as well, provided it’s big enough that the tire cannot ride over the top if the vehicle should move. Once you’ve got your chock in place, make sure the car is in park if it’s an automatic, or in a high gear (3rd or 4th) if it’s a manual. If you are working on front pads, make sure the parking brake is applied. If you’re only lifting a rear wheel to change the brake pads on the rear (provided your car has rear disc brakes), you’ll not want to set the parking brake, or you will not be able to remove the rear calipers.
Loosen, but do not remove, the lug nuts on the wheel you wish to remove, then use the jack to lift the vehicle. Once you have the car lifted high enough for the tire to be off the ground, lift it a little higher, then place your jack stand under the car on a suitable support structure to secure it. You can then lower the car using the jack, onto the jack stand. Leave the jack raised up to the vehicle however, it will support the car should the jack stand slip.
Once the car is securely lifted, remove the wheel, and locate the brake caliper. It’s the large chunk of steel that appears to be wrapped “around” the rotor, the round shiny “disk” also made of steel. In most cases, the bolts that hold it to the suspension are around the back, and are sometimes “recessed” in rubber grommets. Loosen one bolt, then loosen the other, before removing either. This will prevent the caliper from moving around and making it difficult to loosen one or the other. If you’re not sure which way to turn the bolt to loosen it, remember this: “Lefty loosey, righty tighty”. Looking at the driver’s side caliper then, to loosen the bolts from the back side means you would turn your ratchet in an clockwise direction, and tighten them in a counterclockwise direction.
Once you have the caliper removed, you can then take out the old pads. Keep the “inside” pad in place however, and use the “C” clamp or channel lock pliers to push the piston back in its bore. Be careful not to damage the rubber brake hose in the process. Simply place the clamp on a solid portion of the caliper, then carefully crank it down onto the old “inside” pad to push the piston back in. You’ll know when it’s all the way back in when it begins to feel “solid”.
Now remove the old inside pad and replace it with a new one. Make sure you get the correct pads on the correct side of the car by checking the location of the wear indicator on the old pads. Some are located on the inside pad, some on the outside pad, and some are on both. In any case, they are usually located on one end of the pad or the other, and should be reinstalled in the same orientation as the old ones.
While you have the caliper off, be sure to check the rotor for excessive scoring or grooves. If they are present, and deep enough to catch a fingernail on, the rotor should be either resurfaced or replaced. Many auto parts retailers also have an adjoining machine shop, and can resurface your rotors. If you find they do not, they can refer you to a local business that does. Generally speaking, if a rotor is fairly smooth, and does not have an excessive buildup of rust, it does not necessarily need to be resurfaced. If however you noticed a vibration upon braking before you began the pad replacement, the rotors are most likely warped, and should be resurfaced. Keep in mind that rotors DO have a lifespan, and once they are worn or resurfaced to a certain thickness, then it is imperative to replace them. Part of the design of the thickness of a rotor is to help dissipate the heat generated by braking, and if most of that thickness is removed, then they can become excessively hot. Excessive heat means there is a greater possibility they can become warped, or “out of round”, and that translates into vibrations in the brake pedal upon braking.
Now that you have your rotors inspected, and either resurfaced or replaced, you can reinstall the pads and the caliper. When reinstalling the bolts, thread both of them in a few turns before you tighten either one. You may have difficulty installing the second bolt should you install and tighten the first bolt. Once the caliper is reinstalled and the bolts are tight, reinstall the wheel and hand thread the lug nuts to the studs. Then use your four-way or tire wrench to tighten them down till they are snug, but not tight. Raise the jack to lift the vehicle off the jack stand, remove the jack stand, and then lower the vehicle till the wheel just touches the ground. You can then use the tire iron or four-way to securely tighten the lug nuts. Then just lower the jack all the way, take it out from under the car, remove your chock, and congratulations, you just finished your first brake job!