no clue what the deal is with this brake ordeal...
I think the booster isn't keeping pressure in the lines or something... when the trucks off it feels like it has a good stiff pedal but once it starts up the pedals gone.. have to press it nearly all the way to the floor before it will do anything.
got a friend that has a 85 22re sitting so i'll be pulling the MC off that and mounting it to mine to see if the booster is infact bad or leaking...
The booster doesn't keep pressure on the lines. It's only function is to assist in applying the brakes. If you have stiff pedal with the truck off, and no pedal with the truck running, your booster is fine; it's job is to make it easier to push the pedal.
I think your master cylinder is not supplying the volume to make those big brakes function.
