With the master below the floor its recommended to run a 2lb inline residual valve with a disc. set up. Has anyone experienced a valve to sticking and lock up the brakes. Just Had the rears lock up. when I cracked the line the pads released. How important is this valve ? I understand with out it you'll have more pedal travel.

I'm no expert but, I just dealt with the valves for the first time on a recent build for my future father in law. He did most of the leg work but, questioned if he needed these things too. Everyone he asked said that they're a must. Without the gravity assist of a firewall mounted master cylinder, all said that the fluid would drain back into the master easily and potentially create dangerous situations with brake performance.

Again, I'm not expert and neither is he but, we did not want to take a chance. Do you?

It may be helpful in your situation to know, we did have issues with the valves after instal. We had issues with them sealing up. He bought a new one to replace one of the valves. Upon inspection and comparison to the new valve, that was the exact same brand, you could tell the quality of the original sucked. After the new one was installed, no issues but, the truck only has 84 miles on it as of Saturday so; we'll see how they do going forward.

I don't recall the brand we used but, we got them from Jegs. You may want to remove and inspect the quality of the valve(s) you have.

Check the pedal free play to make sure it isn't holding pressure on the M.C,

Is the valve installed in the correct fluid flow direction?

What FBS said. They are directional and its just a simple relief valve

valve is in correct. I ordered a replacement . seems that the pressure from my foot was held in place by the valve or is it the master for some reason. Ill drill out the old 1 and see what happens anyway with out the relief valve and pedal travel.