Rear brake caliper pistons won't go back in...

[MrClancy]

Anyone have any suggestions for getting the rear brake pistons back into the calipers? Thought I would put a fresh set of pads on all the wheels today. The front pads went in easily, and the pistons were easily compressed back into the calipers with a big C clamp. The rears have been another story altogether. I can't seem to get the pistons to push back into the calipers to make room for the thickness of the new pads. There is a slot on the pistons that is positioned properly to accommodate the tab on the back of the new pads, but just can't get the room I need to push the caliper back on. The pads are the correct pads. Perhaps the pistons have seized, but I wouldn't have expected both of them to do that. Is there something I need to do with the handbrake? I did loosen it underneath just in case that was impacting it, but that didn't seem to help. I think there is something obvious I'm missing, but none of the manuals indicate any other step. Should I take the dust seals off the pistons and soak them with penetrating fluid? Any thoughts would be appreciated! Would prefer not to have to buy new rear calipers, but maybe thats the direction this is going. Thanks.

[SpecialTool]

I'm not 100%, since I haven't got to that part of fixing mine yet, but I think the rear pistons are the screw in type. You have to twist them either CW or CCW to push them in. You should be able to find a universal tool at a local auto parts store that looks like a cube with holes and tabs on each side for retracting the pistons with a ratchet and extension. Now it someone confirms that they are actually screw in...

[SoFlaFiat]

Yep, they screw in, a c clamp will do nothing but frustrate. Clockwise.
I've seen some guys post pictures of cool homemade tools to do the job. Do a quick search on the forum and you will see endless info on the subject.

[MrClancy]

Cool! Thanks guys. Harbor freight has a big parking lot sale tomorrow. Will head down there and pick up that weird looking cube tool... and maybe a new rolling tool chest while I'm at it.. !

[bobplyler]

I don't think the cube will work on the Fiat calipers. I've just used a motorcycle tire iron.

[SoFlaFiat]

I've never used the cube, but I have seen posts here where it was termed "a tool everyone should have in their box" so, I'm thinking it must have worked!
Hit the parking lot sale!!

[vandor]

I use a large screwdriver and/or vice-grips.

[kilrwail]

The cube works if you're patient.

[MrClancy]

There's a tab on the back of each of the pads in the rear. What purpose does that serve? It seems to get in the way...

[BEEK]

the tab keeps the piston from turning. the ratchet / screw self adjuster inside the caliper requires the piston to not turn so it can take up the slack and keep the handbrake working

[MrClancy]

got it. thanks. I did get one of those cubes, and it did work. One caliper was fairly easy, the other one took a lot of strength and patience. Thanks to all for your posts.