tire pressure on motor home

With the proper pressure gauge (straight on end with no angle) you should be able to check the inner rear tires with no difficulty - after you remove the wheel cover. I took mine off a few years ago and left them off. The outer duals are tough if the valve stems aren't long enough to reach with the angled back end of a tire gauge. I use a small, inexpensive plastic extender on those two wheels. I have not had any trouble with them so far but I do carry spares and the means to pump my tires up to pressure. I understand extenders may fail causing serious loss of pressure. They tend to fail when checking the pressure, perhaps getting a bit of dirt in the seal, which isn't dangerous because you are stopped. A special tool to remove and install the extenders is probably a necessity. I use a 6 inch piece of plastic hose from the hardware store with a wood dowell handle.