So, I'm rebuilding the rear calipers on my 87 GT w/ 3800. Got everything disassembled. It didn't take too much effort, but I have a few questions.
1. What should I use to polish the bores & the surfaces with lots of corrosion build up. The E-brake shafts were nearly frozen due to rust and corrosion between the shaft, shaft dust boot, and caliper housing. There is a little corrosion on one of the shafts too. There is a small amount of corrosion on the inside of the bore, all the way at the back where the shaft seal sits. Is this something I can hit with a small piece of steel wool?

2. Is Honing necessary? There isn't much scoring or scratching of the cylinder. It looks a little worn farther back where the back end of the piston sits. Everything around the seal groove looks good. Both pistons appear to have a good finish and don't need anything.

3. I am also trying to replace the rubber hoses going from the steel lines to the caliper, but cant get the fitting to break loose. I bought flare wrenches last night, so still have to give that a try. And its been covered in WD-40. Anything else I can try? Can I heat it up a bit?

Thanks in advance.

Replacing hose... Heat metal end on hose should work to release steel. Don't try to heat the steel part.
Warning... Likely have corrosion on the steel line inside the "nut." You like needs replacement of steel lines.

Rebuild rear is often a waste of time and money. Even if shell is good, piston is not made to be a DIY project. Was not made to be service by GM dealers etc. Bad pistons then junk them.
If you have New pistons and when shell is ok rebuild can work but your shell is very bad condition... You can easily damage the aluminum when trying to clean the mess.

Bore does NOT need a hone etc... because bore make no contact w/ the piston.
Damage/corrosion the Seal areas, piston and/or screw, then the seals will leak or won't last.
very easy to happen on screw hole. Just a scratch inside the screw hole can cause a leak. The important seal goes on the screw. washer "seal" just keep water/dirt away from the screw hole.

See my Cave, Rear Brakes and Brake Service
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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 07-31-2013).]

fiero fish, What I describe here makes me unhappy, but it has worked repeatedly for me. Vice grips on the steel line hex nut. Use the straight jaw variety and clamp down very hard so a second attempt or scoring is avoided. The fittings have always come loose. They do laugh at flare and even new open end wrenches.

yes, dont be scared to break the rear metal lines. they are easy to replace, and cheap. they start at a TEE right by the rear passenger wheel well.

So, I took the time to rebuild the calipers cause even if it was going to be a waste, I wanted the experience of pulling them apart, seeing the internals etc. I got the flex lines replaced after buying the flare wrenches and getting creative by rotating the flex hose off the steel line instead of turning the end on the steel line. No leaks in that area. (It was really amazing how easily they broke loose after I bought the flare wrenches)

Unfortunately, my brakes lasted about 2 days, and never felt quite right. The pedal now feels pretty spongy and the car nose dives like its using just the front brakes again. The calipers did have a fair amount of corrosion/pitting around the E-brake screw seal, thus I think its time for new calipers. The calipers are not "leaking" but are damp around the E-brake screw, so they are probably just sucking air when the pedal is released. Also, my E-brake doesn't release all the way yet, but I think that's a cable issue, cause the levers on the brakes were turning quite freely.

Thus leading me to my question: Where's the best place to get a new/reman caliper? And for the remans, how do they fix the issue of a corroded caliper housing. Do they bore it out bigger or something and replace with a larger seal? I just don't want to get a new caliper and have the same issue.

Any info would be appreciated. Thanks,

You could try calipersonline.com

They are located in SE Michigan.

Otherwise, I get calipers from the local store, or from rockauto.

I completely avoided this whole issue by putting 86 Grand Am front calipers and rotors on the rear of my 86.

This is from the NIFE web site.
http://www.fierofocus.com/T...%20Rear%20Brakes.pdf

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Project Genisis Lo Budget 3800SC swap

88 Coupe under construction