Jowee

I recently purchased a 95 DX coupe from a friend that's been sitting around undriven for the last 4-5 months. He thought the front brakes needed to be replaced and were just locked since the has been sitting. So, I replaced the front calipers, rotors, pads, lines and brake booster with new parts from Auto Zone. After flushing the system multiple times, the front brakes seem to lock up after about 2 miles/15 min of driving. Once the car is parked for about 10-15min or I disconnect the hose that goes into the booster, the brakes release and it's back to normal.

Cliff notes: 95 DX replaced: front calipers, rotors, pads, lines and brake booster. Brakes slowly lock up and pedal gets firmer & firmer after some driving. Problem goes away after car is parked for 10-15 min or vaccume line is disconnected. Any ideas wtf is wrong with it?

Any and all help is appreciated