one brake piston is stuck out

[2WICE]

anyone ever had a piston on a brake caliper stick all the way out when pushing the other in?
i have 4 piston calipers on my 4runner, and when doing my pads today i opened the bleed to push the pistons in so i can fit the new pads and put them over the roter.
when i pushed one of the pistons in, the other piston, on the same side extended all the way out, and now wont go back in for the life of me.

im using some big channel locks to squeeze the pistons.

anyone had this before? i have an apointment with a fabrication shop 2morro that iv been waiting on for awhile so i need to get this done today or im really screwed.

 

[greasefingers]

I have not preformed this task with 4-caliper piston brakes before. Obviously the two pistons are connected hydraulically. Did you remove the master cylinder reservoir caps? When you push the piston in, the fluid must go somewhere. If the cap is not removed then you simply pressurize the system. With the cap removed, the volume will rise, so watch it and remove some if necessary.

 

[2WICE]

makes a lot of sense.. gonan check ti out when i get back over to my truck...

 

[greasefingers]

Also:
The best way to move the pistons back in, is to use the old brake pads (in place) and use a c-clamp. That way both pistons see the same force and move together. You will not scratch the piston surface with the tool, this way.