The valve you are talking about i believe is a proportioning valve. we used them in dirt track cars to get the front to back braking to be either more or less pressure in either direction. In the case of a truck, if you have no load, you could use it to reduce the pressure to the back so they dont lock up, and have more pressure if its loaded. look at them as if its a trailer, because they use the same kind of system on trailer brakes.[/quote]
Demo Man, thanks for that anology. Thinking about it in terms of a trailer brake makes a lot of sense. So I'm looking at one of the compact adjustable proportioning valves available since my truck typically won't be hauling a load, and, my bed is all aluminum (pretty light). I can see the rears locking up pretty easy if I don't cut the pressure down.
