Are you changing the rear at the moment or the front? The rear piston needs to be turned as it goes in like a screw, the front is standard piston you just push in with a clamp or brake tool. Or are you talking about the sliders have seized? Pull it apart and clean and relube.

 

All 4 corners probably aren't locked up at the same time.

Is it an automatic? (P) would hold the front wheels in place.

The rear caliper can be damaged by pushing it straight in. They make special piston tools for the rear. to compress and twist at the same time.

Worst case scenario, loosen the bleeder screw at the caliper. But that should be totally unnecessary. But possible if things are broken.

And yes, deffiantely lubricate the sliders while you're doing all this. That'll help keep any 1 caliper from sticking.

 

rent disc brake caliper tool from Crappy Tire (free with CC deposit)

 

All 4 corners probably aren't locked up at the same time.

Is it an automatic? (P) would hold the front wheels in place.

The rear caliper can be damaged by pushing it straight in. They make special piston tools for the rear. to compress and twist at the same time.

Worst case scenario, loosen the bleeder screw at the caliper. But that should be totally unnecessary. But possible if things are broken.

And yes, deffiantely lubricate the sliders while you're doing all this. That'll help keep any 1 caliper from sticking.

All 4 corners ARE locked that's the problem. It's not an automatic so I don't know what is up with the front.

I'm going to have to try the bleeder screw, I've tried everything else...

And thanks for the Crappy Tire Tip Ewa, I'm going down there straght away...

 

If you have worn brake discs and worn pads it is possible for the piston to project slightly out of the caliper bore....this allows the piston to jam and refuse to return though it would be one in a million to occur on all 4 wheels at the one time.

 

Try the bleeder screws on the caliper and reset the pistons all the way. If the pistons in the calipers are good, they will reset with little problems with the bleeder screws open. If thats the case and they lock up again, work your way backwards. The only 2 other components would be the brake regulator and master cylinder. ABS module maybe?