I took a rear brake caliper apart using your write-up, everything went fairly well but it is a bit different because of the parking brake setup.
I wasn't too sure how to proceed so I went with the trial and error thing. The piston didn't want to come all the way out (I tried pulling it, shooting compressed air, etc...) so I put the caliper in a vise and rotated the parking brake bracket like this:
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart4.jpg">
After rotating it a bit, there was a "give way" (which is not good most of the time) and after taking the caliper off the vise, it looked like this, the piston had slid out.
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart5.jpg">
Now I don't know how come it slid out that much, I didn't rotate the bracket that much. To completely remove the piston, I had to rotate it counter clockwise with the piston reset tool.
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart6.jpg">
Then I realized that there was a huge screw holding the piston in the caliper.
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart2.jpg">
I don't know if I went too hard on the caliper but the screw appears to be a bit crooked (leaning to one side, not straight). I tried to re-insert the piston but I can only re-thread it a little bit.
There is a snap ring at the bottom of the caliper piston port.
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart1.jpg">
I think it's to remove the whole screw setup, I wonder if I should remove it to see if I bent something and if it is a serviceable part.
Any hints, pointers, etc...? I'll do the other one tomorrow and I don't want two screwed up calipers on my hands!!! Thanks in advance.
Here is a pic of the sandblasted caliper (ready for ceramic coating) beside the other one.
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart3.jpg">

 

there is no need to turn the parking brake "bolt" like in my first pic, you just need to unscrew the piston and it comes off easily. The screw on the second one is perfectly straight. The screw on the first one is deviating to one side, I used a pair of pliers and I can move the screw around (it moves easily, I tried recentering it but it keeps going back to the deviated position).
Do you know if I can replace this part by removing the snap ring? Anyway, I'll try to find some long nose snap ring pliers this morning and see what I can come up with. I don't think they sell that internal part seperately, might have to buy another caliper (goddamnit).
Thanks in advance.

 

for a reasonable price. I bought a refurbished caliper for my car a year ago for about $100 + core. New was something like double that price.

 

I will buy a rebuild kit to put them back together. The only thing is that the screw seems to be on a "cartridge" held by a snap ring. I wonder if I can buy the "cartridge" seperately because the way that the screw goes sideways on the one caliper, there is no way the piston will be able to slide in the caliper.
I guess I should check if ETKA lists any brake rebuild kits and see what they include.

 

when I had my B5 S4 calipers powdercoated. While the seals were fine, I debated getting them rebuilt with the kit since they were off the car and there was no easier time. I talked with the shop that does rebuilds and they indicated the seals were fine and there was no need.

So, I think a kit is out there, but I'm not sure what's exactly in it.

Good Luck!

 

Thanks, this is a "long term" project so I have a bit of time to research this...

 

You figured it out on a second try, which is not too bad. As for the 1st caliper, I honestly am not sure what is happening. It seems like though that you may have bent something by holding the piston the vice and forcing the caliper around.

There is a nut that holds the e-brake mechanism attached to the caliper - take it off and see if there is easy acces to that internal bolt/stud. Also try releaseing the snap-ring and taking it apart. Sometimes you get lucky and can reasemble it all without any damage, but I honestly don't know what happened.

 

I brought it back to the center but it won't stay centered. I tried threading the piston but it only goes in a bit and then gets stuck. It's pretty damn hard to find snap ring pliers that will fit but I'll work something out. Perhaps I'll see the light when it's all apart (more than it is right now I mean).
Thanks for your input, much appreciated.

 

&lt;I tried threading the piston but it only goes in a bit and then gets stuck&gt;

Dis you do this by hand? If so, try the actual tool on it now....it may be just fine because once it goes in there is no other way....HTH.

 

I can thread the undamaged one all the way by hand.
I figured out what happened, I used the "if you don't understand it, destroy it" technique and realized what I did wrong (my caliper is useless now though).
Because of its orientation, I couldn't get the snap ring out so I used my 20 ton shop press instead and this little unit here came out (you can see where the parking brake bracket attaches and where the piston screws in).
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart7.jpg">
Then I put it in the vise and took it apart (there's a spring in there, I found out when I received the top part right in the forehead).
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart8.jpg">
The two "screws" are isolated from each other, that's why turning the top screw did not affect the bottom one. Anyway, everything looked pretty straight, except for the housing because it had to "skip" over the snap ring but I think the crookedness came from this:
<img src="http://i132.photobucket.com/albums/q33/x1rider/apart9.jpg">
See how the spring is not "square" anymore, I probably damaged it when I rotated the parking brake screw with the caliper in the vise, which in turn caused the piston screw to deviate to the side (this is why I could move the piston screw around, it was only seated on the spring).
I wonder if they sell that little unit on it's own (I doubt it).