2 new mastercylinders,new powerbooster,new front calipers and hoses.bleed brakes good pedal,start truck pedal sinks slowly to floor.does not stop quickly. any ideads???also smokes when started and pulling a trailer

 

did you bleed the rears first ?

from the top ..... right rear , left rear , right front , left front , .... of course check and top off in between ..... use a small clear hose ... place it on the bleeder screw ... pour fresh fluid in a decent size bottle ... place little hose in bottle with the tip under the fluid ( I start with about 1/4" of fluid to start) ... slowley have someone depress the pedal while you open the bleed screw ... the need to verify " Floor" then clos the bleed screw and the they need to verify " Up " ( do not pull up on the pedal you will be sorry ) ... do this at all 4 corners and you willl notice a difference ... if not Pm me and will go further...

also check to make sure your rear shoes are correctly adjusted .... should be just slightly dragging ( but just barley ) in the drum this is just about right .... any less then slight drag and you will have a mushy pedal until they adjust enough .... which can take a long time .... .... keep posted on results

 

did all that pedal is good and hard till u start the dang thing up then pedal slowly sinks to floor

 

then your master cylinder is goin into bypass and is no good ... if you just bought it tis faulty ... I promice .......