Ok.  Bear with me and I'm sorry if this is a stupid post, but I have to ask because I'm at wits end.  Is there some place that's best to go to get everything aired up?  I only have a little 2 gallon air tank and it was taking me 10-15 minutes to air up one tire.  So I went to one of the service stations and it wasn't much better.  I went to a truck stop (albeit a run-down place) and I was trying to air one tire up and I lost pressure (and no it was not leaking from me not connecting it well).  It seems (to me) that the air station didn't seem to have enough pressure to overcome the pressure in the tires.  Doesn't seem logical to me that there would be a difference but I can't come up with anything else.  I've checked the stems for debris (even though I keep the little cap thingys on them).  They hold pressure after they are aired up, so it's not that they are loosing air faster than I can put it in.  I don't pull a lot and I have a couple of very slow leaks (new set on the way).  I know it's important to keep optimal pressure when pulling but when it takes me over an hour to get everything aired up it makes me more inclined to change my mind and stay home....

I asked at another truck stop if they had a special place to air up the 18 wheeler tires and the guy looked at me funny. 

The truck stop is the best place to air up.  They have to have air at least 80 PSI... Some truck tires need 120 PSI.   It'll fill your tires fast.  The little air tank you have is really only good for a bicycle tire.  Remember, your just equalizing the pressure in your tank and the tire.  Bring your tire guage to make sure the tires are at the correct pressure.

Fill your trailer tires to the max pressure on the sidewall.