How to replace the pads on your car's disc brakes.
*** NOW UPDATED *** with new retaining clips. See photos step 14.
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Step 1: Gather Materials
- new brake pads
- brake disc lube (high temperature synthetic grease)
- probably, new retainer pin spring clips
- floor jack or other jack
- lug nut wrench
- assorted screwdrivers and pliers
Brake pads come in several flavors, named (in order of increasing high-techiness):
1 organic -- old style asbestos
2 semi-metallic -- fitted to most new cars
3 metallic -- usually used on race cars
4 ceramic -- the New New Thing in brake pads
Since you're saving beaucoup $$$ by replacing your own pads, it certainly does not hurt to spend a few extra bucks for the next better pads than the factory pads.
For instance, in my case, my car (1997 Ford Escort LX wagon -- not-too-sexy!) was factory equipped with semi-metallic in front, and organic in rear. I bumped up to ceramic in front, for $18 more, and if I were to do the rear, I would probably fit semi-metallic.
Step 2: Raise Car and Remove Road Wheel
Remove the road wheel to expose the disc and the brake caliper.
If you're doing front brakes, you may wish to turn your steering wheel to afford better access to the caliper.
XXXTRA SAFETY TIPS:
- put car in gear
- apply parking brake
- chock wheels
- stash road wheel UNDER the chassis while you're working on the brake. That way, if you have your head stuck in the fender well and your car falls off the jack (against all odds), the chassis will fall on the wheel, and hopefully your head won't be squished like an overripe cantaloupe.
Step 3: Remove Retaining Clips
At the back of the caliper, you'll find two complex-shaped little twisty spring clips. These springs hold the retaining pins in, which in turn hold the brake pads in.
Using needle nosed pliers and a flat blade screwdriver, remove these spring clips.
The ones on my car are broken, so the tangle doesn't make much sense in this photo. I'll add new photos when I get the new clips.
Step 4: Back Off Pads
Using a screwdriver, VERY GENTLY pry between a pad and the disc, or better yet between the back of the pad and the piston.
Your objective is to compress the piston very slightly, so you can easily slip the old pads out.
Step 5: Remove Retaining Pins
Now, remove the two pins which actually hold the brake pads in place in the caliper.
As shown here, I used a SMALL hammer, and a drift punch, and gently tapped them out. You may simply be able to grab the head with pliers and twist/pull it out.
Step 6: Remove Pads
Now withdraw the pads, one at a time, from the back of the caliper.
Step 7: Inspect New Pads
Now for the moment of truth: Get your new pads out of the box, and compare their shape to the old pads.
If all is well, go on to the next step.
If all is not well, then you're scrood, because now your car doesn't work and you have to go back to the automotive store :( Hope you've got a bicycle or a motorcycle handy!
Step 8: Compress Piston
Since your new pads are obviously much thicker than your worn-out pads, there's not enough space to put your new pads in place.
So, you need to compress the piston back into the caliper.
There are many ways to do this; probably the safest is to use a C-clamp around the piston and the back of the caliper.
I couldn't do this, so I used a GENTLE prying technique between the caliper and the piston.
Be careful not to scratch, mar, or bend your brake disc. And be careful to exert pressure *straight* on the piston, as much as possible.
Step 9: Test-fit Pads
Test fit your new pads into the caliper, to verify you have compressed the piston sufficiently.
Step 10: Replace Pad Shims
My pad kit came with new pad shims. So I removed the old shims and installed the new.
These shims carry all the braking load from the side of the pad, to the caliper. So make sure to lubricate them with high temperature synthetic disc-brake grease.
Step 11: Prepare New Pads
- stick backing pads (if supplied) to the back of the new pads with self-stick adhesive
- grease the area of the back of the pad which will contact the caliper or piston
- IMPORTANT: grease the edges of the pads where they will contact the pad shims (see previous step)
Step 12: Install Pads
Install the new pads into the caliper
Step 13: Install Retainer Pins
Grease the retainer pins with disc-brake lube, grease the holes they're going into, then install them into the caliper, through the holes in the pads.
Step 14: Install Retaining Spring Clips
- withdraw top pin temporarily
- thread top pin through second clip (the "M" shaped one)
- install first clip (vertical one) into pins
- clip one side of the "M" through the hole in one brake pad
- clip the other side of the "M" through the hole in the other brake pad
Step 15: Reinstall Road Wheel and Test
Reinstall the road wheel.
Get in the car and pump the brakes a few times. Since the new pads were installed with a loose fit initially, your brakes will feel squishy for a few strokes until the pads come into contact with the disc.
When the pads come in contact with the disc, the brakes should feel normal and firm.
If all is well, slowly road test the car.
Congratulations! You just got your hands dirty, and saved a couple hundred bucks.
Be sure to dispose of all used brake materials in accordance with local and state regulations.