Dumb tire question, 2007 Itasca Navion

Tire Man (Chuck) is in Ridgecrest CA and phone (760) 446-3546

DuallyValve/Borg (Bill) is also in CA at (818) 352-8717. I hope that's the right number - I can't connect to their website.

I think some of their valves are of common manufacture. You cannot go wrong with either line. I installed the first valves I found (Borg), and Bill was very helpful when I damaged one and needed a quick replacement.

Last I checked, the two outfits packaged their kits differently. Some were four wheel (duals only) kits, others were for six (including fronts). Some included "air through" caps and some didn't. And I think both suppliers offered chrome or natural brass.

The "air through" caps speed tire checking up even more. Those are available at NAPA for those who are interested.

Bill, best to go over to the View/Navion group on Yahoo groups and join there to get the correct info.
We've had 2 Sprinter RV's with the dual rear wheels. It is the pits to check the air on the inner wheel. You do have to remove the stainless wheel covers to check the air. Only issue with that is every time you remove the covers, they get looser & looser with the result that eventually they will come off easily while you drive down the road. You sure don't want that as they are $$$ to replace, even though they are Chinese made.
Best way to solve the dilemma is to install solid brass valve stem replacements on the rears. They are kinda expensive initially, but solve the problem entirely. Borg Tire supply sells them among others. I have a set sold by The Tireman in Northridge, CA. They are wonderful. Takes all of 3-4 minutes to check all 6 tires. Only issue is getting them installed, as they have to be done right the first time, or you have leaks, so you need a good tire place to do them.
One other thing with these is you can't rotate except side to side, as they won't work on the fronts. Fronts don't need extensions anyway.
By the way, this is not a Winnebago issue, it's the way Mercedes supplies them to the RV makers. And don't be surprised if you get these extensions installed that the tire place that you have do them points out to you that the stock stems are not rated for over 60psi pressures. That is correct. Again, the way MB supplies them

The tires have separate valve stems. There are aftermarket equalizer gizmos, but they're quite obvious—they have a sort of hose going to each valve stem, and a little fitting in the middle with a valve and usually a sort of pressure gauge (or at least a flat/not flat indicator).

You have two stems hidden in the gap between the wheels. The one on the outer wheel points inward, and the one on the inner wheel points outwards. It's possible that one or the other has a bend to bring it to a more convenient location, but they at least start off in those directions. They may be hard to see through the holes in the wheel, but they're there. I think usually they're set up to be at approximately opposite sides of the axle—at least that's the way they are on my motorhome.

Unless you have fancy curved valve stems or extensions, you use the nozzle thingy at tip of the pressure gauge (or inflation chuck) for the inner tire, and the one facing backwards for the outer tire. If you have more a passenger car style of gauge with a single connector, it probably won't work out.

Valve for the inside wheel should be accessible through one of the holes in the outside dual wheel. It faces the space between the wheels, not the back side where the disc is. Many RVers use extensions or special longer valve stems, but the tires should be able to be serviced using dually pressure gauge and dually chuck if the hand holes are actually big enough for hands.

BillHoughton wrote:
We have a new-to-us Itasca Navion, and I'm exploring the mechanical bits. I went to check that my new tire pressure gauge would fit the fill valves on the tires today, and am confused about the dual rear wheels. There's a fill valve sticking out from behind the outside tire, through one of the holes in the wheel; no sign of any other fill valve there. The inside wheel is inaccessible, the center of the wheel being filled with the disc brakes. Does this one fill valve fill both tires?

There should be two fill valves - one for each tire, unless someone replaced the two with just one - which is a bad idea (because if one tire has a leak, both will go flat).

If there is a wheel cover (wheel simulators), remove it to make sure the fill valve is not behind it.

Bill