How to lower my ride? Please help a newbie.

[los-lowrider]

Yesterday I tried it the first time with the new air tank. And now I have the next problem, I use the air lift two valves block which seems not be able to switch under pressure. So I would geuss I need an 3/2 way valve which deflates block after each switch. Is this correct and has anybody here done this because I have no idea which relais would work.

Additionally I just don't believe the pressure shown on the display is correct.
Any comment is welcome. I will see how it turns out. Maybe I should invest at this point in the new digital air lift management kit to be on the save side.