How to Fix Your Brakes
Disc Brake Pad & Rotor Replacement
Replacing the disc brake pads and rotors is a job that can be performed by intermediate do-it-yourselfers with a moderate amount of experience. This is not a job for beginners as there are safety related issues that can arise from performing the job incorrectly. It is important to consider that, once the repair is underway, more significant wear or damage might present itself and require work beyond the scope of this article. The repair may also require bleeding the hydraulic brake fluid system.
Some mechanics recommend simply swapping the old brake pads for new ones. Referred to as "pad-slapping," this method is not recommended. At minimum, the rotors should be machined and resurfaced before installing new brake pads. But most brake rotors on today's vehicles are too thin to machine. It has become routine — and surprisingly cost-efficient — to replace the rotors along with the pads.
The repair steps found here include replacement of both the rotors and the pads. Make sure to allocate time during the repair to have the rotors machined by your local parts supplier if they are not being replaced. The procedures will be similar for most makes and models on the road.
Finally, in order to complete this repair it will be necessary to lift and support the vehicle with a jack and jack stands. Failure to follow safe lifting practices can lead to serious injury or fatality.
Parts & Tools Required
Here is a list of basic tools, materials, and parts that you will need:Parts:
- Brake Pads
- Brake Hardware Kit
- Floor Jack and Pair of Jack Stands
- ½" Socket Set and Ratchet
- Breaker Bar
- Torque Wrench
- Brake Piston Compressor (or large C-Clamp)
- Wire Brush
- Large Hammer (3-4 lb.)
- Pry Bar or old Flat Screwdriver for prying
- Optional: ½" Pneumatic Impact Wrench
- Copper Anti-Seize Lubricant
- Silicone Brake Lubricant
- Thread Locker
- Cotton Rags or Paper Towels
Before You Begin
Before you begin repairs, it is wise to follow a few basic safety precautions. While this job does not require a lot of tools, it is important that you make sure to use the proper tools to prevent injury to yourself — or damage to your car. Use personal protective equipment such as a pair of gloves to protect your hands. Shield your eyes with safety glasses or goggles. And be aware of anyone who might be in the area of your repairs.
Since you will be lifting the vehicle off of the ground, make sure that your vehicle is on a solid, flat surface. Put the vehicle in park and set the parking brake. Place a wheel chock or wood block behind a rear tire to further prevent the vehicle from rolling while you lift it off the ground.
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Once you have ensured your safety, and the vehicle is in position for repairs, you are ready to begin.
Lift the Car with a Jack and Jack Stands
Using a breaker bar and socket, loosen — but do not remove — all of the lug nuts.
To raise the entire front end of the car at once, locate a solid lift point underneath the front of the vehicle (suspension crossmember, etc.). If you cannot find a suitable lift point in the center, raise one corner of the car.
Place a jack stand under the recommended lift point(s) or under a sturdy frame member and slowly lower the vehicle onto the stands.
Leave the jack in place and in contact with the vehicle as an added safety measure. Remove the lug nuts with a ratchet (or impact wrench) and set them aside with the wheel. Place the wheel under the rocker panel for added safety. Turn the steering wheel all the way to one side to expose the brake caliper and to make removal easier.
Remove the Caliper, Caliper Bracket, and Rotor
Using a breaker bar, loosen the two caliper bolts. Remove them the rest of the way with a ratchet.
Separate the caliper from the caliper bracket using your pry bar to work it free. It is important to suspend the caliper using wire or a bungee cord to prevent strain on the hydraulic hose - do not just let it hang.
Check the caliper bolts/slide pins for corrosion or wear. Clean or replace as necessary. Slide the old brake pads out of the caliper brackets.
Use your breaker bar to loosen the two caliper bracket bolts and remove them the rest of the way with a ratchet. Check for evidence of thread lock on the bolts. Remove the caliper bracket from the steering knuckle and set it aside.
Remove the old brake rotor. The rotor may resist coming off due to corrosion on the back side. Use a large hammer to smack the face of the rotor, turning the rotor as you go. Avoid damaging the wheel studs with your hammer. The rotor should break free.
Clean and Inspect the Wheel Hub and Caliper
With the rotor out of the way, clean any corrosion on the wheel hub with a wire brush or sandpaper. Spray it with brake cleaner and wipe dry with cotton rag or paper towel. Clean the caliper bracket in the same way.
The new rotor comes with a protective coating of oil from the manufacturer. Use brake cleaner to remove the oil from both sides before installing the new rotor. Once it has been thoroughly cleaned, set the new rotor on the wheel hub and hold it in place with one of the lug nuts (or the retaining screw). Install the caliper bracket. Start both bolts before tightening either one to prevent cross-threading.
Inspect the caliper piston. Clean any residue on the edge of the piston with a rag soaked in brake cleaner to prolong the life of the caliper. Be careful not to soak the rubber bushings with cleaner. Also, check the level of the brake fluid in the fluid reservoir. If the level is high, you may need to remove some of the fluid before you compress the caliper.
Reinstall the Brake Rotor, Caliper Bracket, and Caliper
Next, using one of the old brake pads and a caliper piston compressor (or a large c-clamp), compress the piston back into the caliper slowly and steadily until the piston bottoms out. Do not force the piston — the fluid can back up into the master cylinder and overflow. Another option is to loosen the bleeder screw located on the caliper to relieve the fluid pressure while compressing the caliper. Make sure to contain the fluid that is released from the bleeder. Some calipers require a special tool that rotates the piston rather than compressing it — usually on rear disc brake systems.
Remove and replace the old brake hardware clip(s) with new ones. Use copper anti-seize lubricant on the surfaces where the new brake pads come in contact with the caliper bracket. Also, apply anti-seize to the new clips and to the back sides of the brake pads.
Now insert the brake pads into the caliper bracket. Clean the caliper guide pins and coat them with silicone lubricant.
Set the caliper in place over the pads and insert the caliper bolts. Again, use thread lock where there is evidence of prior use and torque fasteners to specifications.
Reinstall the wheel and hand-tighten all the lug nuts.
Repeat the procedure on the other side of the vehicle.
Lower the Car, Torque the Lugs, and Pump the Brakes
When both sides are complete, raise the vehicle off of the jack stands, remove the stands, and lower the vehicle until the tires touch the ground. Torque the lug nuts to the manufacturer's specification in a "star" pattern using a torque wrench. Lower the vehicle fully and remove the jack.
Start the vehicle and pump the brakes several times to build up pressure in the braking system. Check the brake fluid level again and top off if necessary. Follow up by taking your vehicle for a test drive to ensure that the brakes are in proper working order.
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