replacing calipers

does it actually have pressure? if it froze, could it be possible that the line its self cant build the pressure like it used to? it might put out enough to force the fluid through, but after that enough resistance just stops the flow... meaning no grip... I am assuming that you ahve fully twisted the piston into the caliper, and then (with the caliper not installed to the hub) pumped the brake to see if it even works? if it wont even do that then start at ground 1 and put your thumb over the brake line (disconnected) and see if the presure can force liquid out with you plugging the hole. if not, you have a pressure issue... if it does, replace the caliper again

also, when changing, i am assuming you didnt let air seep back into the module, correct? from my understanding if air gets that far back into the system you are hosed till you get it to a dealer to haev them fix it.... however, this would affect the entire system, not jsut the one side.

if you are really running out of ideas, once you have taken a shot at mine, then you might want to perform the same diagnosis on the opposite side rear brake... see if its the same on that side or not.

Torinalth

If you unscrew the brake fluid reservoir cap, and twist the piston inward, if there is air in the system, it should force it back up and out the reservoir. However, a few good bubbles could splatter on to your paint.

Did you try bleeding it at the master cylinder? theres two bleed screws, one for the front, one for the back. Wouldnt hurt to bleed them both.