Front brakes freeze up after driving!?!

i have a 1985 4x4 toyota pickup, ran great then the brake pads went bad... no big deal. also the master cylinder was going bad so i replaced the pads with the more expensive pads from autozone, new rotors, new mastercylinder, and new wheel bearings.

so heres the problem. i drive it around after a bit the brake start sqeezing the rotor without me touching the pedal. when i parked it i put loosened the mastercylinder bolts to see if maybe it was the brake booster was out of adjustment and was still pushing some on the mastercylinder. however that didnt losen the brakes. so i losen the bleeder and the calipers loosens. so i am pretty sure is a hydralic problem not a mechanical problem but i am still confused where it might be. this is my 2nd new mastercylinder so i dont think its that. its both of the front calipers not just one so i dont think they are bad.

anyhelp would be great. suppose to leave to go out of town in 6 hours =\

thanks in advance

Zachary

i think it might be because my dumbass was to too cheap to buy brake fluid so when i filled my mastercylinder i put AT fluid in and and that would make expand when hot.

u just screwed up the whole hydraulic brake system...

replace ALL components...

new to the forum.
I am having the same type of problem. replaced master, calipers, pads, and hoses. Still have problem. hope someone can help.