Front Brakes Locking On After Car Idles.

We have changed front hoses, bled system(probably enough to have flushed old fluid out) unhooked booster vacuum to remove it from equation, I fabricated an 18 qauge heat shied fashioned from photos of factory shields to reflect heat from master, I adjusted drums in case they were adjusted to high, it just seems fluid is expanding and locking them on when engine gets warmed up.