
Project in question:


They're airbag helper springs that sit between the rear leaf springs and the frame, to keep the truck level and not wreck the soft stock leafs when hauling a lot of weight.
I want to be able to monitor and control the pressure in them (5-50psi) and the tank (100-200+psi) from the cab. I could buy a control system, but it would be $300+, which I don't feel like spending on something I should be able to make for a lot less.
This is the basic idea, not to scale:

Basically looking at 2 options each for monitoring/control. Either run hose up to the panel with regular gauges, or pull apart digital tire gauges and extend sensor or lcd. Either use 4 solenoid valves or run hose to panel and machine a set of spool valves into aluminum to have push button control.
And the panel has to be compact, clean and attractive - a bundle of plumbing parts isn't an option here, not that there's anything wrong with that

I will work on some more drawings and finish pricing out options, but any initial thoughts? I promise eventual video of more exciting uses than airbags for on-board air, potentially from fridge compressor in custom tanks! 8)