Question

hello I have a 1984 gmc flat bed truck with a hydroboost brake system . I have developed a very strange problem with this system ,my front brake calipers start clamping down on my truck as I am driving down the street or just siting and engine runing, brake pedal just gets rock hard and I CANT MOVE THE CAR , I have to get out open the hood with a line wench loosen and bleed out the pressure in the line closses to the hydroboost unit, or the back line on the master cylinder witch releases front brakes an Im good for a while then it does it over an over . it happens with car cold or hot when ever its running . I have replaced master , hydro unit ,front calipes ,front perpotion valve, brake lines ,cleaned rear weihgt trasfer valve,changed rear brake lines, flushed brake system,its happenig more and more often. hope some one has experienced this type of problem an share their experience .name is gary you can contact me at (edited for privacy) and ask for gar

Edited by Maureen on 4/24/2008 at 6:04 AM