plasticman
I have the same year truck Model 6400 and I bled a quart of fluid through it and came up with the same result, no pressure until the very end of the stroke or lots of pressure after a couple of pumps? Then after doing what I should have done first and read the manual. I jacked up each wheel and adjusted the brakes unil they started to drag a bit and then backed them off a tad! I went from a little pressure at the end of the stroke or pumping the brakes, to about 3-4 inches of trvel and rock solid on the pedal and plenty of stopping power!!!
Set of your brakes and then give her a try.
Good luck
DS
