Lexus Repair: 94 Lexus LS400, lexus ls400, intermittent problem

Question
Intermittent problem with the brakes not releasing.  (Normally after brake use in traffic).  Have changed the brake lines and master cylinder, swapped out the fluid,  turned the rotors and new pads since the last ones were worn due to the problem.  Two weeks now and the problem has returned?  

Answer
Replace the spring that pull sthe brake pedal back into position? & make sure nothing under there is in the pedal's way.
Best way to do it is slide & lay the seat all the way back & just lay down sorta upside down on the seat. Hard to bend sideways & actually work up under there.