So where the hoses are terminating is just a valve cap on a standard Schrader tire valve. Unscrew the cap and put some air in with whatever you have handy to inflate tires; I would not be at all surprised if they're working just fine as designed.
If they're Firestone Ride-Rite units (and I'd guess they are), the pressure limits are 5 psi to 95 psi if memory serves--they say to always have at least a tiny bit of air in them to avoid damage, though I've never heard of any being damaged from lack of air. I wouldn't be surprised if the system is working fine as designed. I find around 40-45 psi works nicely for me on my motorhome, which of course is an entirely different unit and model than yours.
Having a built-in compressor tied into the system and valving to be able to adjust on the fly for sure is a nice feature, but not essential to be able to use the air helper springs.