How many of us are there? Owners of Dodge based RV's?

New question. I know this is going to sound stupid, but this is my first RV and I have no manuals.

I'm sure these have to do with leveling the RV (1978 Robinhood, Dodge chassis Class C) but what do I do with those small air release valves on the back (no, not the ones on the tires :))? If I let air out, where do I put it back in? What are they exactly?

Thanks,
Stephanie