We recommend Internet Explorer set to 1024x768.

© 1999 Brian F. Schreurs
Even we have a disclaimer.

So we found ourselves with a set of trashed front rotors. Fortunately, the PBR calipers make it pretty painless to swap them out. We contacted Dal at Lambert Buick, the best place to get genuine GM parts, and ordered a pair of GM rotors (#1806230). They come in AC/Delco boxes but the're made by ITT/Aimco.

One of two large bolts holding the caliper to the steering knuckle. The other is directly below it.

Start by removing the cosmetic lug nut caps and loosening the lug nuts. Both are 3/4". Then lift just the driver-side wheel off the ground. There is a frame rail right behind the wheel well which can take the weight. Don't lift on the plastic fender or you will pop it off.

With only enough lift to allow the wheel to spin freely, finish removing the lug nuts.

The caliper has to come off. We found it was much easier to remove the caliper with the brake pads out of the housing. Look at the bolt at the top of the caliper. The bolt can be removed with a 12mm socket; the little spacer thingy just on the inside of the carrier, which only has two flats, must be held steady with a 16mm wrench. With this bolt removed the caliper should just swing backward and down. Ta-daa, there's the pads. They slide out the sides. Be sure to note which is which; they are directional.

Now thread the 12mm bolt back in just enough to hold the caliper to the housing.

The housing is held to the knuckle with two 18mm bolts. These are located on the back of the housing. Stick your head around there and they'll be quite obvious. It's hard to hide an 18mm bolt. With these two bolts removed, the caliper will fall off.

Wait! You don't want the caliper to fall off. You'll damage the brake line. Be ready with something to use to tie the caliper to a fixed point, such as the A-arm or spring. We happened to have some mechanic's wire so we used that. Remove the lower bolt first, then loosen the upper bolt, and hold the caliper with one hand while you finish the bolt with the other. Then hold the caliper with one hand while tying it off with the other. Fun, huh?

Caliper safely hanging out of the way and rotor removed.

With the caliper out of the way, the rotor pulls right off. Easy.

Put the new rotor back on. Then put the caliper over it. The rotor won't move around so much (getting in the way) if you put one lug nut on the stud closest to the ground. Tighten down the caliper. Be sure to use threadlock on the 18mm bolts during reassembly. Failing to do so could cause the bolts to back out while you're driving. The sound of that caliper smacking your wheel will get your attention -- we guarantee it. Plus, the bolt is not sold separately by GM; only as part of a $60 bracket kit. Local hardware stores probably won't carry 18mm bolts, particularly not in 10.9 hardness (grade 8 equivalent, which you need for this particular application). You'll have to find a replacement at a bolt specialist. Ask us how we know all this.

Use threadlock.

Open the hinge. Odds are, the upper pad spring probably fell out; it just sets in the groove at the top of the housing and is held there by the pads.

The caliper pistons will probably need to be compressed. Use a compression tool designed for the job, or failing in that a C-clamp will do it if you are careful. Once the pistons are compressed far enough to clear the pads, close the caliper and tighten the 12mm bolt.

Put the wheel back on (take off that spare lug nut, if you haven't already). Tighten it down to 100 ft-lbs. Drop the car and redo the procedure on the passenger-side.

That's it! Easy!

Not only did we replace the rotors, but we also went back to stock GM pads instead of the Carbotech Panthers. So it's hard to say whether braking was improved. But braking is definitely a lot safer now that the rotors are in spec. And the job was fairly painless, which is a nice change for a late-model car. Not everything has to be a contest of wills.