Brake pad replacement is a common maintenance procedure that every driver has to do eventually. Making sure your pads don't get overworn ensures that your car is going to stop effectively when your press the pedal. However, having a shop replace your pads can be expensive. For those people who are a bit more mechanically inclined than others, replacing the brake pads on your own may be worth the trouble. Generally, replacing the pads on your car can be accomplished in a few easy steps.
Tools and Materials
- A few clean rags
- Some old newspaper
- A good set of tools
- 2 good-sized blocks of wood
- A flashlight
- A container of brake fluid
- A sturdy car jack
- A stand to support the car
- A sturdy piece of wire (like a coat hanger)
- Your new brake pads
- A large "C" clamp
- Some latex or nitrile gloves (optional)
First, park the vehicle on a level surface and set the brake. Take the blocks of wood and put them behind and in front of one of the rear tires (or the front if you're replacing the rear pads). This is to ensure that the vehicle doesn't move.
If you've recently driven the car there's a good chance that the brakes will be extremely hot. Let them cool for awhile before touching them.
Loosen the Lugs and Jack up the Car
Loosen the lugs on the wheel you are going to be servicing until they spin freely, and then raise that wheel with the jack until the tire is no longer touching the ground. Then lower the car onto the stand, being careful to use one of the frame contact points that are identified in your owner's manual. Other places on the vehicle are not designed to support weight and will be damaged if you use them to lift or support the car. Once the car is situated on the stand make sure that it is being supported in a stable manner, and that there is still plenty of space between the tire and the ground.
Remove the Wheel
Removing the wheel should be a snap. Simply spin off the lugs the rest of the way and carefully pull it away from the car. It should easily dismount and you can set it aside. If the wheel wants to spin when you try to loosen the nuts then try re-checking the parking brake or putting the vehicle in gear.
Remove the Caliper
The first thing you will notice when removing the wheel is the disc, or "rotor." It is a shiny circular disc that is mounted directly behind the wheel. Mounted over the disc is the caliper, which houses the pads. First check the rotor and caliper to ensure that they are cool to the touch and then feel around the back of the caliper. You should find two bolts on the back, one on each end.
Sometimes brake calipers are mounted with special fasteners like TorxÂ® head bolts. In this case it is going to take a special tool to remove the caliper. Take a look at the bolts and find out what size they are. Use the appropriate wrench to loosen them. Pull the caliper away from the disk, it should come off cleanly. At this point it is essential that you don't put any pressure on the brake pedal for any reason. Doing so will damage your braking system. Once the caliper is removed, support it by hanging it on the wire so that you don't put any pressure on the line.
If you are replacing pads on the rear wheels, and you can't get the caliper to slide free of the rotor, check to make sure your parking brake isn't set. If the parking brake has any pressure on it, it will prevent the caliper from being removed.
Remove and Replace the Pads
Take care to note exactly how the pads are mounted, then remove them. The cup-shaped component located on the inboard side of the caliper is called the piston. Use the "C" clamp to compress the piston back into caliper. Replace the old pads with the new ones, being careful to follow the instructions on the package.
Reassemble the Components
Putting everything back together is easy; just follow the steps in reverse order. Make sure that you tighten the caliper bolts securely, but don't over-tighten them. Repeat the steps for each wheel you intend to service.
Remember that every vehicle is different. If you run into any problems it may be a good idea to invest in a Chilton's or similar auto repair guide for your specific vehicle; especially if you intend to continue doing repair work yourself.
All of this will help drivers take matters into their own hands, where a set of disc brakes is in good shape and just needs brake pad replacement. Never perform this job when the brake rotors are broken or misaligned, as this is a more serious brake problem. Also inspect the disc for excessive grooves that indicates bad rotor wear.