I believe that a remote reservoir mounted up on the firewall will eliminate the need for the residual pressure valves, no mater the location of the master.
The residual valves are supposed to do the job that the weight of the fluid in the lines above the wheel cylinders did before.
Have you ever "gravity bled" your brakes? You simply fill the reservoir, crack a bleeder, and wait for fluid to drip out. The fact that this works tells us that there is an unobstructed passage from the reservoir, through the master, and to the wheel cylinders. If the reservoir and wheel cylinders stay in the same location on the truck, and then you move the master cylinder down a few feet I don't see as it would make a difference in how everything worked. There is still the same weight of fluid over the wheel cylinders. Do you follow?
What I can't explain is how my original 52 has the master under the floor with no residual pressure valve. Then when I put a newer master in the same location, even with the reservoir about 4" higher it is recommended I use the valves?
Grigg
