Steps for changing your brake pads

Step 1. Remove the wheel.
Step 2. Remove the slider bolt.
Step 3. Pivot the caliper up.
Step 4. Slide out the old brake pads.
Step 5. Replace the retaining clips.
Step 6. Slide in the new brake pads.
Step 7. Retract the pistons.
Step 8. Monitor the brake fluid level.
Step 9. Reposition the caliper.
Step 10. Reinstall the slider bolt.
Step 11. Repeat for the other side.
Step 12. Test-drive under safe conditions.

Remove the wheel

Loosen the lug nuts on the wheel. Then jack up the car and place a jack stand under the car's frame. Lower the floor jack so its weight rests on the jack stand. Fully remove the lug nuts and remove the wheel. You now have access to the brake assembly and can safely reach under the car.

Remove the slider bolt

Find the two slider bolts (sometimes called "pins") that hold the caliper in place. On this car, a 2009 Ford Flex, the bolts are on the inside. The arrows in the photograph above point them out. It's generally only necessary to remove the lower bolt. It can be long but once it is fully loosened, it will slide out easily.

Pivot the brake caliper up

With the bottom bolt removed, the brake caliper pivots up, as shown in the photograph above. The rubber hose, which is the hydraulic line, will flex to allow this so do not disconnect any hydraulic brake lines. If you think you have to disconnect a brake line, you're doing something wrong. Reassemble the brakes and seek professional help.

At this point, it is very easy to inspect the thickness of the brake pads to confirm that they need to be changed. Most brake pads have metal wear indicators, which are small metal tabs that squeak when they contact the rotors. Even if these are not yet touching, the pads are worn out if the friction material is one-eighth of an inch thick or less at any point.

Slide out the old brake pads

The brake pads are now exposed and the retaining clips hold them loosely in place. Simply slide the old brake pads out, as shown in the photo.

In the above photo, you can see a comparison of the new, thicker brake pad (top) next to the old, worn-down brake pad (bottom).

Replace the retaining clips

The photo above shows the pad's new retaining clips. New pads almost always come with new clips, which allow the pads to slide back and forth easily. Use the new ones and chuck the old ones. There are no retaining screws for the clips. They just snap in place. There are usually left-handed and right-handed clips, so change one at a time, making sure they match up exactly as you go.

Often, a small packet of graphite-based grease will come with the brake pads. Apply the grease to the clips of the new brake pads to keep them from squeaking, as shown in the photo above.

This photo shows that the new brake pad has a riveted-on shim, which is the thin metal plate. Some brake pads might have unattached shims that have to be temporarily held in position until you lock the pads in place. The "ears" are the metal tabs on either end of the brake pad (only the two left ears are visible here). These ears fit into the slots in the clips. Some of the grease can be applied to the ears and between any loose metal shims too.

Slide in the new brake pads

The new pads slide into place as easily as the old ones did when they came out, though sometimes the new clips will be tighter. The ears of the new pads should slot nicely into place on the brake grease you applied.

Retract the pistons

In the photo above, the arrows point to the pistons. These pistons press on the brake pads and squeeze the rotor to stop the car. Your car might only have one piston for each wheel, but the principle is the same. Before you can lower the caliper into place, these pistons need to be retracted (pushed back) so that they will clear the new, thicker brake pads.

Do-it-yourselfers often use a C-clamp to retract the piston or pistons. In this case, we simply levered the piston back using a 2x4 and a piece of plywood. By doing this, the brake fluid in the pistons is being pushed back into the master cylinder reservoir through tiny passages, so the pistons move slowly. The width of the 2x4 allows both pistons to be pushed in at once. If you pushed in one by itself, the other would pop out — you don't want that. Fortunately, most cars have just one piston per caliper, which makes things far simpler. Either way, steady pressure and patience are key here. In this example, we added a second plywood shim near the end of the process to fill the ever-increasing gap. Throughout, take the utmost care to ensure you don't nick or tear the rubber boot and seal that encircles the pistons.

Monitor the brake fluid level

When you push the pistons back, the brake fluid level slowly rises. Open the master cylinder reservoir and check it often. This is more of a concern when you work on the second brake because the combined fluid volume of two calipers could cause the brake fluid to overflow. If it looks like this is going to happen, suck out some of the brake fluid with a turkey baster. There is more danger of overflowing if someone topped off the fluid level during regular service visits. (This is why the brake fluid reservoir shouldn't necessarily be topped off like that.) The fluid level naturally goes down as the pads wear. And it comes back up when the pads are replaced. As long as the level doesn't go below "MIN," the arrow shown in the photo above, on the lower half of the reservoir, everything is cool.

Reposition the caliper

With the pistons retracted, the caliper should slip over the pads with little effort. Sometimes the fit is tight and the caliper will slide on the newly installed brake pads. If the pistons catch on the brake pads, you might need to check that you retracted the piston completely.

Reinstall the slider bolt

Reinstall and retighten the slider bolt. Straighten the car's wheels, remount the tire and tighten the lug nuts.

Repeat for the other side

Repeat all these steps for the other side of the front brakes. Remember that the brake fluid will be higher in the reservoir now that new pads are installed on one side, so keep your eye on the fluid level as you retract the piston on the other side. The fluid will only rise more the second time around. You don't want it to overflow since the brake fluid is highly corrosive. If it looks as if the fluid will overflow, suck some out with the turkey baster. If the level is below the "MAX" when both sides are done, add fresh fluid to top things off to the line.

Test-drive under safe conditions

Test-drive the car under safe conditions to make sure everything is working properly, being especially careful for the first few stops. Be aware that your brake pedal might have a higher engagement point. You will quickly get used to this change. Enjoy using your new brakes knowing there are now thick brake pads to stop you safely.