Brakes locking up

[Rambo]

A few weeks ago my brake booster gave out so i replaced it. Had to unbolt the carb, remove clutch cable, remove master cylinder, and move some lines in that area. Put the new booster back in three times as the first time i mounted it the wrong way on the mounting plate and the second i forgot to put the seal in.It was a long struggle bleeding, as the fronts were being stubborn and i had to bleed it without the engine running and somehow without the vaccuum boost it worked. The brakes felt good so i took it for a drive drove about 15 miles( everything was flawless) and suddenly i was fighting agaist the brakes. The pad were smoking and the brake pedal was all the way up. After 20 minutes it unlocked and i drove home with the e brake (i didnt want to put pressure on the brakes). My main suspect is the auto zone brand dot -3 fluid but i will try (under safe conditions) to recreate the problem. If i get it to lock up i will lossen the MC bolts from the booster to try to rule out things. I dont think it was the booster rod adjuster nut as that was adjusted properly and i think it wouldnt take 5 miles for that to cause a problem. Before i run some more test to rule things out i wanted to see if any of you guys would know what could cause this or have had this happen?

Thanks

[So Cal Mark]

it wasn't the fluid to begin with, but if you've boiled it I would replace it. The problem is most likely the pushrod adjustment. As the brakes drag and overheat, the lockup will worsen. An easy way to check it is to loosen the master cylinder nuts when the brakes are dragging. If loosening the cylinder unlocks the brakes, you need to adjust the pushrod

[Rambo]

Thanks mark i know that wasnt the problem to begin with. The MC loosening test is exactly what i plan to do. I think im going to flush it out anyway after i solve whatever the problem is. The only thing is that the adjustment is bottomed out right now. The brakes were dragging slightly without the wheels on and me turning it by hand but with out any wheels i thought that was normal.