Need info on installing a dump valve

Hey folks, I'm sure what I need to know is posted in here somewhere but I cant seem to find a clear enough explanation so I'm gonna ask for some advice. I've got a 98 utility combo spread, the leveling valve is on the rear axle and controls all 4 bags and I've stared at it trying to figure this out but I'm obviously missing something. I want to put a dump valve on the rear axle and control it electrically in the cab. I got the whole wiring thing covered, I'm needing to know what valves do I need, how to hook it up and any other info you all might know about it. I'm trying to prolong my tires as much as I can and I've heard a dump valve is a good start. Any help would greatly be appreciated and I hope everyone has a great new year and we all make some money

 

I tried drawing pictures, lookin at it then drawing a few more pictures and the end result was a bunch of pictures that looked like hell and a headache from staring

 

Well I dont think mine is quite set up like that, I'll try to explain so bare with me....on the left and right side there is a 3/8 air line that runs from the front bag to the rear bag, then there is a T on each side kinda up on the top, off of those lines that come down behind the crossmember right behind the front axle that T into the line coming out of the HCV. the other line on the HCV goes to the air tank and the pressure valve for the air supply. so its like all the bags would drop if I put one on it instead of just the rear like I need. Whoever had this trailer before I got it installed a single line off the left rear bag to a ball valve with a gauge on it for who knows what but I can open it up and bleed the air off to squat the ### end. I'm just like #### could it be set up any more crazy