84 4x4 lspv replacement with aftermarket valve
 

Ok i have bought an aftermarket valve from summit. I got to looking at the factory lspv and it has two line in one going out. Trying to figure out if one of the lines is a return or if it needs to be blocked off.

The way the LSPV valve works is....When the brake is pressed the front of the vehicle does a nose dive, When this happens the valve opens and allows more fluid to go to the front brakes preventing the rear from locking up and skidding. (I believe I am correct and not backwards on that)The more I think about it, I think I am backwards, I think it allows more fluid to go to the back brakes so the front doesn't lock up. So anyways, Yes that is somewhat of a return and if you want to keep these actions of the brakes, then I would recommend keeping them attached. I just bypassed mine completely and took out the line that goes back to the front brakes. I havent had any problems yet. but I haven't driven on wet or snowy roads with it either. I hope this helps....

Ok so it doesn't need to be blocked off

No. It can be but doesnt need to be as long as it is connected to something....You dont want to just leave it connected to nothing!!