I have a 2004 G35 COUPE with the bremo package. I Changed my pads for the first time and i can't get my pistons back out i think. because i cant get pressure back to the pedals. I tried bleeding the system from the calipers and only got very little stopping power. Can some one help asap thanks allot.

Back out? ie... you pushed them in to give the pads more room to fit? That's a normal procedure but I don't compress them in any more than I have to. Did you purposely push them WAY in?

Front or back?

Front. yes i pushed them in just about all the way

With what? C-clamp? You didn't unscrew the bleeder when you did this right?

No i didnt was i suppose to? yes i used a c clamp

No unscrewing the bleeder isn't necessary. I don't see why it wouldn't pop out again once you stepping on the brake. The piston seems to be stuck somehow.

anyway to fix this?

Couldn't you remove the caliper off the rotor, then push the brake pedal down? The piston should probably slide back out since it no longer has any resistance. Then you can tighten it back down with a C clamp as necessary... The piston should definitely be moving. If it's still stuck inside after you try that, perhaps there's air in the line? It's possible that the caliper might be in need of a rebuild or the piston is damaged, but that's unlikely...

Anyways, if it's still stuck you will have to remove the caliper, and follow the rebuild procedures to pop the piston out using an air compressor (I think that's the typical method).