I'm currently installing a set of Ride-Rite airbags on my 1995 F250. I'm also going to be installing a dual leveling setup for them. But, since I don't feel like shelling out a lot of money for a branded kit, and settle for the capabilities of those systems I thought I'd build my own. I'd like to pass my design of this through you guys before I start assembling it to get some input, and maybe catch something I missed.

Component list:

Viair 45050 IG continuous duty air compressor
5-gallon tank 2 x 3/8 npt ports, 2 x 1/4 npt ports
6 port 1/4 npt manifold
4 x Viking Horn V504 air solenoid (inflate/deflate for each side)
2 needle gauge to monitor pressure of each side
2 x check valves
2 x 5/16-24 SPDT reed switches to set ride height
DPDT (on)-off-(on) rocker inflate/deflate switch
SPST compressor master switch
90 on/ 120 off pressure switch
145 psi safety valve
filter/regulator set to 100psi
fittings, air line, accessories as required

I'll have the two switches in the space in the instrument cluster, and mount the gauge somewhere nearby. The master will control the compressor. The inflate position of the rocker switch will send 12v to the reed switches. They will be setup to be normally closed, then open when they reach their set height. These will send signal to the two inflate solenoids. The deflate position will go straight to the deflate solenoids. I'm not sure how fast they will deflate the system, so I may have to put a pressure reducer in to slow it down.

I'll put the solenoids in a box to protect them from water. The compressor will be getting a shield around it for this too. I'm thinking all this will be mounted outside of the passenger frame rail. I'd like to find places inside the frame, but things are pretty crowded under there as it is.

Here is a diagram of my planned plumbing. I'm thinking I might be able to use just one deflate valve if I tee the two sides together with check valves in between. Though the cost of two more check valves is only five dollars cheaper than the solenoid I already ordered.

 

Wow that is a serious system there! I have a portable compressor I just plug into the cigarette lighter socket when I need more air which is very seldom. I run with 15 lbs all the time.

 

Sorry, I don't have time to work through all of your details. It looks like you're being pretty thorough, so I doubt you're missing much (if anything). And if you are missing anything I'm sure you'll be able to figure it out and address it as it comes up. But I do have a few random thoughts that might be helpful to consider.

I'm not sure about putting gages on the bags. I'd guess that you can get some pretty abrupt pressure changes as the tires hit bumps which might wipe out the gages. But maybe I'm wrong about that...

I wouldn't go with a 5 gal tank. It's too big and therefore too hard to fit anyplace where it's not in the way. I've had onboard air with no tank (just the lines) and with a 2.5 gal tank. Your air bags will fill fast enough as the compressor runs that they won't really need a tank. Filling up tires is generally faster with no tank (you'll never have a tank that's big enough to really be helpful, so you're always trying to fill the tire and the tank rather than just the tire). A tank is necessary for running air tools, but in reality, an on-board compressor really isn't any good for running air tools, so I'd just leave them at home. The only reason I have a tank at all is that I use my on-board air for "toad" brakes when I'm flat towing my Bronco. I need to always have a little high pressure air available, and it's good enough for that.

When I had airbags in my '95 F-150 I just had air chucks so I had to stand behind the truck to fill them up or let air out. That wasn't quite as convenient as what you're talking about, but I really only had to change the pressure when I was loading or unloading the truck anyway, so I was already there. I never missed the more complicated system.