Tire valve extensions

[Wanda H]

We thought it would make sense to put tire valve extensions on the inner back tires of our Class C RV. The first ones put on by a RV mechanic only lasted 2 years. We bought 2 from O'Reilly Auto Parts and had our tire center put them on. They are causing our tires to go flat in about a month. What are we missing?

 

[Chef Duane]

Don't use tire valve extensions on the inner back valves of your Class C RV.

 

[Wanda H]

That must be our problem. How can a person air up the inner tire without removing the outside tire?

 

[Gary RV_Wizard]

If you need extensions, avoid flexible types if you can and stick to solid metal. And don't get the cheapest you can find because the gaskets that seal the screw-on connections are the critical piece. And even the metal extensions need to be checked for tightness once in awhile - they can loosen up due to the constant vibration. A friend of mine actually had a hole wear in one because it touched the edge of the wheel where it passed through and road vibration sawed through it. And it was thick metal.
Metal extensions

Here's a tip: You won't need convoluted extensions if you have the tire shop reverse the orientation of the tire valve, such that both rear wheels in a dual pair have the valve pointed outward. Truck tire shops do this routinely, plus they use long valve stems and bend them to the outside. The only drawback to this trick is that you cannot rotate that tire to the front (steer) axle without changing the valve position back to the more usual way.

Another tip: If you don't want to reverse the valves or use extenders, get yourself a dually air chuck, one that has two air outlets, one for the inner valve and the other oriented for the outer. See https://www.amazon.com/air-chuck-dual-wheels/s?k=air+chuck+for+dual+wheels

 

[Onyrlef]

If you need extensions, avoid flexible types if you can and stick to solid metal. And don't get the cheapest you can find because the gaskets that seal the screw-on connections are the critical piece. And even the metal extensions need to be checked for tightness once in awhile - they can loosen up due to the constant vibration. A friend of mine actually had a hole wear in one because it touched the edge of the wheel where it passed through and road vibration sawed through it. And it was thick metal.
Metal extensions

Here's a tip: You won't need convoluted extensions if you have the tire shop reverse the orientation of the tire valve, such that both rear wheels in a dual pair have the valve pointed outward. Truck tire shops do this routinely, plus they use long valve stems and bend them to the outside. The only drawback to this trick is that you cannot rotate that tire to the front (steer) axle without changing the valve position back to the more usual way.

Another tip: If you don't want to reverse the valves or use extenders, get yourself a dually air chuck, one that has two air outlets, one for the inner valve and the other oriented for the outer. See https://www.amazon.com/air-chuck-dual-wheels/s?k=air+chuck+for+dual+wheels

Both my steel extensions, wore through in about a year from contact with the wheel. They won't leak but you can't add air. I repaired mine with flex tape, a short piece of pex tubing and hose clamp.

 

[Onyrlef]

That must be our problem. How can a person air up the inner tire without removing the outside tire?

A truck tire shop can do them right.

 

[Wanda H]

Thank you everyone!

 

[CharlesinGA]

What type of RV chassis? Ford, Chevy, Mercedes?

Your best bet is to have standard high pressure rubber and brass valve stems installed in the wheels and use a dual head chuck.

There are two different types, one has a straight end and an angled back chuck, the other has both front and rear facing angled.

Use one with a 12 inch extension, and install an air hose nipple on it.

Milton S-693-12 1/4" FNPT Extended Reach Dual Head Air Chuck,Bronze

Milton Dual-Head Air Chuck, Twelve Inch 1/4" FNPT, Tire Air Chuck for Tire Inflator Gauge and Air Compressor, S-690-12

Use the Alligator V2B Inflate Through Valve Stem Cap Gator Auto RV Semi (10 Pack) in the place of the original metal or plastic caps on the valve stems.

There are many other brands, however the Alligator caps are the "original" and are made in Germany, very high quality

THERE IS NO NEED TO REMOVE THESE CAPS TO CHECK PRESSURE

These take the place of the caps, and keep dirt and water out. Those are not threads on them, but rather cocentric grooves designed to lock into similar grooves in the tire chuck to make inflating easier.

This allows you to remove the wheel simulator (if you have steel rims) and then reach thru the openings in the outer wheel to check the inner tire pressure. In the same way, you reach thru the opening in the outer wheel at the stem for the outer wheel and pull back toward you with the chuck to inflate or check pressure.

You can find tire gauges with similar angled foots and use these to check the wheels.

There are hard stems such as the Borg stems but on my Sprinter chassis they basically didn't work and I sent them back. The hard stems make it extraordinarily difficult to install the rear wheels without damaging the stems. This was a situation I didn't want to deal with on the side of the road.

The rubber stems give you enough flex to reach them with the chuck and get a good seal for servicing or checking pressures.

Lastly, I did away with the wheel simulators right away and touched up the paint on the wheels and located some plastic Mercedes hub caps for the front wheels. You can purchase hub caps from Pacific Dualies.

RickNC posted these two pics on iRV2 in a discussion about aluminum wheels on Class C's

Late EDIT: Make sure the wheel/tire shop installs the rear wheels so the inner stem is aligned with a hole in the outer wheel! This is an obvious thing that many tire people will miss. Stand there and make them do it.

 

[Wanda H]

Great information. Thank you for taking the time to answer my question.

 

[RayIN]

That must be our problem. How can a person air up the inner tire without removing the outside tire?

I carry a 6" metal valve extension for when the inner dual required more pressure. After adding air the extension is removed and stored in my toolbox.
Then I added TPMS sensors, this extended the stem enough the 6" metal extension hasn't been needed since.

 

[Professor David]

https://www.summitracing.com/parts/pho-amh1

If you have these installed, make sure they know what they are doing…like a heavy duty truck tire shop that has been in business for a bit. Installed properly they work well…installed improperly results in problems.

 

[John From Detroit]

There is a company.. Dully valves as I recall No need for an extension.. Work well.
They are made specific for the wheels you have but here is a link to ONE supplier

https://accu-pressure.com/

 

[Larry N.]

Dully valves as I recall

Probably dually valves John...

 

[chuckbear]

Gary, I don't understand your comment in your post, "Here's a tip: You won't need convoluted extensions if you have the tire shop reverse the orientation of the tire valve, such that both rear wheels in a dual pair have the valve pointed outward." My valve stems are installed this way and it makes it impossible to reach the inner stem to check the pressure or add air since there is no room to reach the inner valve stem. Chuck

 

[Fyrflie]

I used flexible extensions for several years with mixed success. All of them leaked at some point. The valve stems were short and straight which did not allow the use of any type of air chuck unless the chuck was bent to fit the inner valve stems. Once the cheap Chinese junk valve stems, installed by Les Schwab, started to leak at the base, I replaced them myself with quality Brass stems angled at 23 degrees to allow access with a standard straight air chuck and allows for tire rotation if needed to all positions on the coach. The inside duals were still difficult to reach because of the wheel covers, so I opted for solid style extensions that only depress the valve when filling of deflating. So there is no air pressure in the extensions except when being used. So far, no leaks.
This is where I get my supplies.

https://tiresupplynetwork.com/collections/all-valves-tools

There are lots of options available. Good luck.

 

[dktool]

I have used the braided s.s. extensions for decades spanning 3 different rvs, have had 1 die of old age and never had leak issues.
99% of success with these is the installation.
YMMV

 

[Lou Schneider]

That must be our problem. How can a person air up the inner tire without removing the outside tire

The best solution I've found is the Jaco Lightning Series tire chuck. The head is fully rotatable so you can set it to the proper angle to line up with the inside tire's valve stem.

JACO Lightning Series Tire Chuck

The problem with using standard inflation chucks on RV dual tires is the pass through holes in the chrome RV hubcaps are slightly smaller than the holes in the rim which keeps a dual foot tire chuck from aligning properly with the valve stem. JACO's fully adjustable head solves this problem.

 

[Gary RV_Wizard]

Gary, I don't understand your comment in your post, "Here's a tip: You won't need convoluted extensions if you have the tire shop reverse the orientation of the tire valve, such that both rear wheels in a dual pair have the valve pointed outward." My valve stems are installed this way and it makes it impossible to reach the inner stem to check the pressure or add air since there is no room to reach the inner valve stem. Chuck

I probably didn't explain well and couldn't find a suitable picture. Will look around for a photo and try to explain better.

 

[CharlesinGA]

The problem with the JACO chuck that I see is that you have to have good access to it to push the release to remove it. How are you expecting to do that when you have passed it thru a hole in the simulator and then thru the hole in the wheel.

That is my argument for the rubber stems and no simulators, decent access to the inner and outer wheel stems.

Charles

 

[TheBar]

I've used the metal extensions that Gary posted for 11 years so far. If they are properly tightened down so they don't touch the metal wheel or hubcaps they won't get worn through.