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Old 04-25-2021, 01:50 PM
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Black88GTA Black88GTA is offline
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Join Date: Jan 2009
Location: Huntington, NY
Posts: 234
Brake caliper rebuild - information dump, aka things I wish I knew beforehand

So in my quest to get my '92 back on the road, I found that the brakes were all shot from sitting around for 10 years. Decided to replace everything - calipers, rotors pads. The rear calipers were just balls of rust, so I decided to get new coated ones from Rock Auto rather than mess with them. The front calipers were stuck from sitting, but otherwise in nice shape - turned out they were plated for rust prevention, and then painted. All of the replacement front calipers I could find on Rock Auto were untreated, so either I'd have to paint them, or end up with rusty calipers again after a couple weeks. So, I decided to rebuild the front calipers instead of replacing.

Turns out, you can get a basic rebuild kit (piston seals / boots) and new pistons off the shelf with minimal hassle and cost, but NOBODY sells a kit for the 3 little rubber boots that go over the sliding sleeve and the lock pin. Except Subaru, who wants to charge $45 IIRC for a single caliper rebuild kit. Thanks guys .

So I started pulling up listings for similar cars on Rock Auto trying to match up the boots I had with pictures, which was kind of a crapshoot. Then I got the idea to email Carlson (who makes most of the brake kits they sell on RA) and Dorman to see if they could cross-reference the boot numbers and tell me which kits had those pieces in it. Dorman wasn't able to do it, but Carlson came through in a big way. Turns out, they were able to do exactly what I asked and gave me part numbers for cheap, readily available kits that include the parts I needed. I was able to find all 3 (although in 3 separate kits ) but each kit at least included two of the boots, so you can do both front calipers with one of each kit. And have a bunch of weird ones left over to add to the misc parts stash. I suggested that they pack these 3 into a kit for the SVX (since they're making them anyway) and they could be the only ones who sell a kit for our cars, but I have a feeling that won't go anywhere.

Anyway, I figured I'd save someone else the detective work on the boots and post the results here for reference, along with other misc information

Subaru P/N for a rebuild kit (includes all 3 pin boots, piston seals, piston boots, and a bit of grease): 26297PA010 Easy mode, but most expensive option.
Boot # 20894 (rear side of caliper, fits over sliding sleeve, flange goes INSIDE caliper) : Carlson 16061, 2 included per kit
Boot # 21089 (front side of caliper, fits over sliding sleeve, flange goes OUTSIDE caliper) : Carlson 16065, 2 included per kit
Boot # 22076 (fits between pivot on caliper bracket and caliper body) : Carlson 16081 OR 16198, 2 included per kit

For reference, the pistons / rebuild kits I used for the rest are as follows:
Caliper piston: Centric 146.43006
Piston boot / seal kit: Carlson 15156

In the event you want to use taps / dies to clean up the threads on the front hardware or calipers, be aware that both the lock pin and the mounting bolts are oddball thread pitches that typically aren't included in the standard tap / die sets. I had to get the tools separately. Not sure about rears, as I didn't take these apart. the thread information (at least for my front calipers) is as follows:

Caliper to knuckle bolts (front): M12x1.25
Caliper lock pin (front): M10x1.0

Bonus round: Torque specs!
FRONT:
Caliper bracket to knuckle bolts: 51 - 65 ft-lb
Caliper lock pin: 25 - 30 ft-lb
Hose attachment banjo bolt: 11 - 15 ft-lb
Bleed screw: 5.1 - 6.5 ft-lb

REAR:
Caliper bracket to knuckle bolts: 34 - 43 ft-lb
Caliper lock pin: 16 - 23 ft-lb
Hose attachment banjo bolt: 12 - 14 ft-lb
Bleed screw: 5.1 - 6.5 ft-lb

Hope this helps someone out, it took me a bit to track all this down. Wanted to dump it in one place to hopefully save someone else the hassle.
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Ebony/Gray '92 LS-L, @123k - bought 01/17/2010, parked for 10 years. Getting back on the road.
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