Replace Your Brake Pads

By Matthew Wright, About.com Guide

Car on jack stand for brake pad replacement.

photo by Matt Wright, 2007

What You'll Need:
• lug wrench
• c-clamp
• open end or adjustable wrench (depending on your car)
• Allen wrenches (depending on your car)
• hammer
• small bungee cord

Preparation
Make sure you've got everything ready to go before you remove your old brake pads. Most important, be sure safety is at the front of your mind. You'll be taking the wheel off so be sure you have your car jacked up and resting securely on jackstands. Go ahead and break the lugs before you jack it up. It's much easier and safer with the wheel on the ground.
Never work on a car which is supported by a jack only! Unless you turn green and your clothes tear themselves to pieces when you get mad, there is no part of your person that can hold a car in the air if the jack slips. You may need to replace your brake discs depending on the amount of wear they have. You should inspect your brake discs regularly.

Remove the Wheel

With the wheel off you can see the brake disc and brake caliper.

Matt Wright

You broke the lugs while the car was still on the ground, so they should be pretty easy to remove. I like to remove them from the bottom up, leaving the top lug nut to be removed last. This keeps the wheel in one place while you remove the rest of them and makes it easier to safely catch the wheel once you remove the last nut. If you remove the lugs and still can't get the wheel off, try this stuck wheel trick.

Unbolt the Caliper

Remove the two bolts which hold the brake caliper.

Matt Wright

On most cars, the next step is to remove the brake caliper so the brake pads will slide out through the top. On a few cars the pads will come out without removing the caliper, but not many. You'll see the brake caliper in the 12 o'clock position just above the lug bolts, riding atop that shiny brake disc. On the back of the caliper you'll find a bolt on either side. It will either be a hex bolt of an Allen bolt. Remove these two bolts and put them aside.
Hold the caliper from the top and pull upward, wiggling it around to loosen it up. If it's stubborn, give it a few taps (taps, not Hank Aaron swings) upward to loosen it a bit. Pull it up and slightly away, being sure not to put any stress on the brake line (that black hose that's still connected).
If there is a place to safely set the caliper back there, do it. If not, you'll need to take your bungee cord and hang the caliper from something, the giant coil spring staring at you is a good spot. Don't let the caliper hang by the brake line, it can cause damage and lead to brake failure!

Remove the Old Brake Pads

The old brake pads will slide right out.

photo by Matt Wright, 2007

Before you pull out the old brake pads, take a second to observe how everything is in installed. If there are little metal clips around the brake pads, note how they are in there so you can get it right when you put things back together. Better yet, take a digital picture of the whole assembly. With the caliper out of the way, the brake pads should slide right out. I say should because in a new car they probably would. Since our cars are not always new, you may need to coax them out with a litte tap of the hammer to loosen them up. If your car has little metal tabs holding onto the brake pads, put them to the side becase you'll need them in a minute. Put the new pads in the slots with any metal clips you removed.
While you're here, it might be a good idea to inspect your brake discs.
Go ahead and slide the new pads into place now, making sure you don't forget any of the little retaining clips you removed earlier.

Compress the Brake Piston

Slowly compress the brake piston.

photo by Matt Wright, 2007

As your brake pads wear out, the caliper adjusts itself so that you will have strong brakes throughout the life of the pads. If you look on the inside of the caliper you'll see a round piston coming out. This is what pushes on the brake pads from the back. Problem is, it's adjusted itself to match your worn out pads. Trying to get it over the new pads is like parking a Cadillac in New York City. You can do it, but the damage level will be high. Instead of destroying your new pads, you'll push the piston back to the starting point. Take the c-clamp and place the end with the screw on it against the piston with the other end of the clamp around on the back of the caliper assembly. Now slowly tighten the clamp until the piston has moved far enough in that you can easily plop the caliper assembly over the new pads.

Re-Install the Brake Caliper

Your new brake pads are ready to stop!

photo by Matt Wright, 2007

With the piston compressed, you should be able to easily slide the caliper assembly over the new pads. Once you have it on there, replace the bolts you removed and tighten them snugly. Press the brake pedal a few times to make sure you have solid brake pressure. The first pump or two will be soft as the piston finds its new starting point on the back of the pad. Put your wheel back on, being sure to tighten all of the lug bolts. Now double-check your lug bolts just to be sure.
You're done! Feels good, right?
Source: by Matthew Wright, About.com Guide