caliper piston

Hey ya'll
I'm changing the pads on a friends '01 miata and the rear passenger caliper piston will not colapse completely. Any suggestions?

Miata rear brake systems require that you release the piston assembly from it's detent compression (due to worn pads) by taking a proper sized hex head/allen key (metric), inserting it into the bak of the caliper assembly, and turning it COUNTER-CLOCKWISE to it's fully open position. At this point, compress the caliper piston with a c-clamp to its original position (flush with the housing assembly. When this is accomplished, and you have installed the new pads, use the Hex key/allen wrench to screw the piston assembly CLOCKWISE until it makes contact and stops (against the new pads/piston wont move further). At this point, use the Hex key to move out the screw 1 to 1.5 turns COUNTER-CLOCKWISE! Now the rear brakes are properly adjusted. Bleed the system, and adjust the emergency brake :)

Thanks for the info below. My dad is working on my 93 mx-5 and was wondering about the set screw. Now how do you adjust the emergency brake? The car came with no manual, etc. I am trying to locate a shop manual so we can work on it.
Thanks


Miata rear brake systems require that you release the piston assembly from it's detent compression (due to worn pads) by taking a proper sized hex head/allen key (metric), inserting it into the bak of the caliper assembly, and turning it COUNTER-CLOCKWISE to it's fully open position. At this point, compress the caliper piston with a c-clamp to its original position (flush with the housing assembly. When this is accomplished, and you have installed the new pads, use the Hex key/allen wrench to screw the piston assembly CLOCKWISE until it makes contact and stops (against the new pads/piston wont move further). At this point, use the Hex key to move out the screw 1 to 1.5 turns COUNTER-CLOCKWISE! Now the rear brakes are properly adjusted. Bleed the system, and adjust the emergency brake :)