Rear Calipers Options

[lsintampa]

75 914/4 2.0

I've rebuilt a small number of calipers over time - it really isn't my forte, but simple enough to do.

Or so I thought.

I'm not sure that I even understand how the rear calipers work on this car. I've never seen pistons screw on and off from the cylinders.

In any event, I'm assuming that the adjusting nut on the outside half needs to come out so I can replace whatever o-rings are under there.

I've soaked this puppy in blaster for two days. I can turn the large nut using a 1/2 inch socket, but then you can't hold the bolt steady and the whole thing turns.

I can barely manage to get a wrench on the nut and then use a hex wrench but the bolt just won't budge.

Question is, since I can turn the whole thing with a socket, would it be OK to adjust the piston that way? I'm worried that with all the turning that the o-rings may be not so good under there.

And just as a side, how the hell does that piston even move? It doesn't seem that it can, so I'm really confused on how this whole system works.

And as another side, what other calipers may work on the back beside these puppies?

Thanks,

Len