If you’re working on your car, one of the things you’ll need to know is how to change rotors on your brakes. It’s not a difficult task, but for your own safety, it’s important that you do it correctly to ensure that the car will stop when you need it to. You won’t need to replace the rotors that often, and you should find that you’ll need to replace the brake pads and brake drums more regularly. When you do so, inspect the rotors. If they’re worn or grooved, you should replace them immediately. It’s always best and safest to buy new rotors as replacements.
Step 1 - Remove the Primary Brake Caliper
Your car will almost certainly have front disc brakes. To get to the rotor, you’ll need to remove the calipers and brake pads (the pads will probably have to be replaced too).
Before you do any work on the car, make sure the vehicle is in park and the emergency brake is on. Raise the wheel with a jack and put chocks under the rear wheels before removing the tire. This exposes the brake caliper.
First, you need to find the two primary caliper mounting bolts. Usually, these will be on the inside or engine side. You can loosen them with a wrench by turning counter-clockwise. If necessary, loosen them with a little oil first. Check to make sure they’re in good shape with solid threads. If not, you’ll need to replace them.
Step 2 - Remove the Secondary Caliper
Lift off the caliper but make sure the brake hose doesn’t become twisted. Underneath is the secondary brake caliper. Loosen the secondary caliper bolts and remove the brake pads. Remove the bolts and lift off the caliper mount. It should come off easily.
Now you’re at the rotor. Often, it will come easily off the wheel mount studs. If not, use oil to penetrate or tap lightly with a hammer. Remove the rotor and put the new one on, making sure to take off the protective film.
Step 3 - Putting It All Back
To reassemble the brakes, there’s more to it than just retracing your steps. Before putting in new brake pads you’ll have to push in, or retract, the piston on the brake caliper. For this, first go under the hood and remove the top of the brake cylinder. This lets any excess brake fluid escape. Next, use a C clamp to push the piston in, protecting it with the old brake pad until it’s fully depressed.
With that done, install the caliper mount and insert the brake pads, including any anti-rattle hardware before tightening the secondary caliper bolts. Finally, re-attach the caliper and tighten all the bolts securely.
Repeat on the other front wheel.
Step 4 - Finishing the Job
You’re almost done but these last steps are some of the most important. You need to bleed the brakes to eliminate any air from the hoses. Do this according to the specifications of the car maker. Finally, push down on the brake pedal then let it come back. Repeat this until the brake pedal operation is normal.
For the first few miles the brakes might not feel as if it's operating as usual but a natural feel should soon return. Also, be aware that smoke will sometimes come off new rotors for the first few miles.