13 replies to this topic

[ragftw]

I have braided valve stem extensions on my inside duals and can not get a pressure reading on one side. I can confirm the tire is not flat but can not check pressure nor add air. Every indicaton I have is the valve core inside the tire is stuck. The braided extension has a core with a very long spring that is probably supposed to press on the core in the tire. Is it normal to leave the core in the tire when using braided extensions? Has anyone had any luck unsticking an inside dual core without dismounting the outside tire?

[ClayL]

There should be a way to adjust it so that the core doesn't operate the schrader valve in the tire stem until you check or add air. It sounds like yours is not adjusted quite far enough in.

That adjustment can be pretty tricky. I installed airless extensions on my last motor home and when I adjusted them I got them so close that when the tires got hot driving through Georgia in the summer, the cores extended enough from the heat to let a little air into the extension where it slowly leaked out. Luckily I was right at a rest stop when both inside duals shredded.

I don't trust extensions anymore and now use metal valve stems that are especially made so as to come out far enough so it is easy to check and add air. They have a grommet that fits in the wheel hand hold so there is support for the long stem coming from the inside dual. They are called DuallyValves. I got mine from Borg Tire Supply. Their site is HERE

The tires have to be dismounted so they can be installed and they aren't cheap but the peace of mind is worth it to me.
It's also very easy to check and add air and they provide a stable support for the PressurePro sensors.

[ragftw]

Clay,
Thanks for the input. Between you and the guys on IRV2 it looks like I will be making an order for DuallyValves. I shredded an inside dual once on another Pace Arrow and the cost to repair the wheel well was $2200. When I look at it in that context DuallyValves are a cheap investment!
bob g

[ClayL]

Clay,
Thanks for the input. Between you and the guys on IRV2 it looks like I will be making an order for DuallyValves. I shredded an inside dual once on another Pace Arrow and the cost to repair the wheel well was $2200. When I look at it in that context DuallyValves are a cheap investment!
bob g

Bob, that's a good way to look at it.

I was lucky and didn't get any damage when mine shredded, but like you, my friend Bud had over $2,000 in damage to a compartment when one of his inside duals went last year.

[nitehawk]

Stay away from extensions if possible. I had the driver's side inside dual valve stem break off just inboard of the threads due to the centrifugal force exerted by the extension. Road repair: $90
Second time--passanger inside dual--same problem, but didn't catch it in time: $561.00 for new tire, air chuck and service in my driveway.

Stay away from the long extensions, buy a straight line air chuck and air gauge, and have some peace of mind.

[ClayL]

The Dually Valve inside dual metal stems come with a grommet that fits in a hand hole in the outside dual rim. There are a lot of them out there and I have not heard of any breaking.

[parmm]

Is there something wrong with the extensions made by Alcoa Wheel when compared to Dually Valves?

Alcoa makes both very good extensions and regular extended valves for their wheels. Alcoa Valve Stems and Alcoa Valve Stem Extensions and Stabilizers. They also make Double Seal Valve Caps, that you can add air thru, but do not leak.

Plus Alcoa Wheel's prices are a lot cheaper and the quality is excellent. Just wondering why not Alcoa Wheel? Their good enough for your tires.

[merv.forney@erols.com]

I added metal extensions to install my Pressure Pro monitoring system and had intermittent pressure readings after about 6 months as well as loss of pressure in certain tires. Heard about dually valves and ordered a complete set for all six wheels. Have not had a problem since they were installed.

BTW, had a passenger side inside dual go bad (tread separation on a Goodyear G670) and Pressure Pro saved me from having significant damage had I not known and the tread completely shredded. A true believer in real time pressure monitoring!

[AFChap]

My Accuride wheels on Spartan chassis came with solid metal (brass?) extensions on the inside duals. Had a cracked valve stem leak early on but no tire damage. I got a pair of the stabilizer for the wheel holes (Alco, though Accuride has them too) and have never had another problem with using solid metal extensions ...several years with double seal air-through-the-cap Alligator caps, and now with TireTraker TPMS sensors ...8 yrs and over 60k miles.

[dachshundexpress]

Hello, I am having flashbacks reading about the flexible valve stems losing air and blown dual tires. I would encourage anyone to remove them. I have been totally happy with the use of nitrogen in my class tires for almost two years now. Then use a dual head tire gauge and the caps that allow you to check the pressure. I have had my tires checked 4 - 5 times each year and the nitrogen has only varied 1 - 2 pounds during each check. 3 or more tires need nothing. Regardless of the stems, caps or monitors, try the nitrogen fill. It is GREAT. Also, I had friends with an American Tradition blow a tire 8 miles short of Key West. Their monitoring system alarm was turned off. The bought the coach used and it was not something anyone thought to check. Take care.

[debrey]

Using nitrogen is new to me. What's the benefit?

[hermanmullins]

debrey,

Welcome to the Forum.

Nitrogen is an inert gas that does not expand in the heat as much as ambient air does. It will also absorb any moisture in the tire. To use nitrogen in your tires you would need to go to a tire shop that has nitrogen, and they will change out the air in your tires.

You can also go to a welding supply store, purchase a cylinder of Nitrogen, an Inert Gas Regulator, and hose. The cylinder will cost you about $200.00 for a 150 cubic inch cylinder plus contents, however that may not be enough for the first change over. The regulator will cost between $75.00 and $150.00, plus the cost of the hose.

While on the road, and you need to add Nitrogen to your tires, you would have to find one of those tire stores or carry you cylinder with you. Nitrogen is good for your tires but if you have a slow leak, bad stems, valve or caps it will leak out just like air and air is less expensive.

Herman

[wolfe10]

Herman,

Let me correct your first statement: "Nitrogen is an inert gas that does not expand in the heat as much as ambient air does."

Both Nitrogen and DRY, repeat DRY air follow Boyle's Law/Ideal Gas Law so PSI increases with increasing temperature exactly the same. PV=nRT applies to both.

The reason for saying DRY air is that many get air at those gas station coin op pumps that do not have air dryers on them. Water is NOT an ideal gas (duh) so water with moisture contend will have more pressure change for a given rise in temperature.

Brett