With the fees charged for maintenance on a personal vehicle in today’s economy, it can be a great advantage to be able to do some repairs yourself. One such task that doesn’t require an entire mechanics tool box or a great deal of knowledge to perform is changing worn out front brake pads. Since a set of brake pads usually cost less than 20 dollars and a maintenance shop can charge as much as 100 dollars to change them learning how to do this task can save good money.
Front wheel disc brakes consist of a rotor, a caliper and the brake pads. The rotor is the shiny disc that you will see when you remove the tire from the vehicle. Attached to the frame around the rotor and sandwiching the rotor is the caliper and in the caliper on each side of the rotor are the brake pads.
Before beginning this task you need to take a few precautions for your personal safety. First decide if you are going to do one wheel at a time just jacking one side of the vehicle off the ground or both sides off the ground at once. Most people do just one side off the ground at a time because the equipment required to do both is not very cost effective unless you are doing this for a living. For instructional purposes we will do one wheel off the ground at a time. We will also assume you have already visited a parts store and purchased the correct brake pads for the vehicle you are repairing.
The first step will be to chock or block the rear wheel in front and back. This can be done with a couple 2X4 pieces nailed together or a 4X4 block. Always block the side of the vehicle on which you are working. After this is done loosen, do not remove, the lug nuts on the wheel you will be removing. After this is done proceed to correctly place a jack under the vehicle and jack the tire off the ground a couple inches. Before removing the tire a safety block needs to be put under the front axle or wheel frame to prevent injury should the vehicle fall off the jack. Now remove the loosened lug nuts and then the wheel.
What you should be looking at now is the wheel spindle which houses the lug bolts from which you just removed the nuts and directly behind the spindle will be the rotor which is the real shiny disc. One thing to take notice of is the condition of the rotor. It should be very smooth and if it isn’t’ it will need to be removed and taken someplace to be lathed smooth again. Most parts stores provide this service at a minimal cost, much less than a shop. For these instructions we will assume the rotor is in great condition.
The next step will be to remove the brake caliper. The caliper is the heavy cast metal thing that sandwiches the rotor between its two sides and is attached usually by two small bolts and it is located at the top of the rotor. It will also have a rubber line attached to it that supplies it with brake fluid. The two bolts need to be removed and then you should be able to slide the caliper upward and off the rotor. Pay attention to how the caliper comes off because it will go back on the same way in reverse.
After you remove the caliper you will see a brake pad on either side of the housing, these need to be removed at this time. Before you can install the new brake pads in the caliper you must first reset the caliper. If you will notice one side of the caliper has a plunger and the other is just stationary metal. Using a medium sized ‘C’ clamp with one side of the clamp on the inside of the plunger and the other on the outside of the caliper slowly tighten the clamp to push the plunger back into the caliper housing. When the plunger is flush with the housing you can then install the new pads. Make sure the non-metallic side of the pads face inward as this will be over the rotor. When this is complete reinstall the caliper over the rotor and install the two mount bolts into the caliper and its mount.
After replacing the wheel and making sure all lug nuts are good and snug lower the vehicle off the jack and then further tighten the lug nuts. Remember, the lug nuts should be tightened from one side to the other not straight around the wheel.
After completing this then it is time to do exactly the same thing in the same order on the other side of the vehicle. Initially the cost of the ‘C’ clamp and a small set of sockets to remove the mount bolts should be less than 20 dollars and after the first time you will not incur this expense again.