HELP! Passenger rear caliper piston will not compress
 

So today I was changing out my brake pads and rotors. Fronts went smooth. Rears were frozen, but the drivers side went smooth. Now, when I got to the passenger side and tried to compress the piston by adjusting the HEX key in the back, they key just kept turning endlessly, and piston never moved. So I figured, might be easier after I dissamble the whole unit, so I removed the caliped, rotor, pads then tried doing it. Now I realize that the HEX piece was so loose, it FELL OUT! Now I'm stuck with a car with no pad or rotor on the passenger side. Any one have any ideas on how to compress that piston so I can install the new pads? Tried searching, got no luck. Also wanted to try to use a C-clamp and push the piston all the way back, but then read this article and didn't http://www.miata.net/garage/brakepad.html

Any ideas?




Thanks in advance,

If the piston won't retract or extend using the hex screw, usually something is seized or a gear is broken. You can try applying a small amount of pressure on the piston as you adjust the pin to see if that works. Otherwise you can get a refurbished caliper fairly cheaply, or if you are up to a challenge, you can get a rebuild kit and rebuild it yourself.

Here are the internals, by the way:
http://www.miata.net/garage/ebrake/index.html

Just FYI
Those hex screws always fall out.

LMAO yeah....you're clearly a n00b at working on Miatas. Just put the screw on th eend of the hex key, insert and turn until piston moves. It's likely that the hex screw wasn't seated all the way down when you were turning it.

its the set screw on the inside of the caliper. loosen the 14mm bolt then unscrew the allen. i think its a 3 mm

Damn hex screw sucks. shit did not move. Used a big ass C-clamp, pads and rotors are in. Thanks for the help guys.