Visit our Popular Forums

Amg · 09-13-2017, 02:39 PM

I would appreciate any thoughts what might have caused two dual real wheel inner tire flats. It is a 2016 Interstate with about 9,000 miles on it. The vehicle is normally in Florida but about 6 months ago I took it North to my other home in Pittsburgh. About that time in Florida I had tireminder air pressure monitors installed. About a month later I noticed that the two inner real wheel monitors were not working registering 0 when the pressure was normal. I called tire monitor and they said it needed an extender to tap the valve better. There are no tireminder dealers in Pittsburgh so I decided to wait until I took the Van back to Florida. Everytime I use the vehicle I manually feel the inner rear tires.

I took a trip to New York City and on my way back decided to stop off in Baltimore. When I arrived I then noticed the two flats. I drove the vehicle about three miles to a tire shop and had him put two new tires on. I could not determine the cause of the flats. There were no punctures but the sides seemed cracked. I wonder if the tireminders may have deflated both tires that were not being monitored. Anybody have any ideas. Thanks

Protagonist · 09-13-2017, 03:46 PM

Valve stems. The inner duals have rubber valve stems. Adding TPMS in place of the valve cap only makes the problem worse, because the stem wobbles as the tire rolls. If the stem leaks, the tire goes flat, and the TPMS should register 0psi. But the tire won't look flat because the outer dual is holding it up.

Alternately, the plastic extensions on the valve stems could be leaking.

I recommend replacing the rubber valve stems with metal ones, and using metal valve extensions, if you are going to use TPMS that attach to the stem.

FlyFishinRVr · 09-13-2017, 04:01 PM

Quote:

Originally Posted by Protagonist

I recommend replacing the rubber valve stems with metal ones, and using metal valve extensions, if you are going to use TPMS that attach to the stem.

FYI for the OP, don't forget to rebalance your wheels due to the added weight, both from the metal stems and the TPMS caps.

Amg · 09-13-2017, 05:47 PM

Thanks Protagonist. When the tireminders were installed they did use metal stems and extensions. When the readings of the two inner tireminders failed to register, the tires were properly inflated when checked. Because of the lack of readings I physically felt the inner tires each time the van was used and again they were fine. It was during one of these checks that I noticed the tires were flat. If it was not the tireminders is there anything else that could have occurred to cause the two flat tires.

Yes, replacement tires were balanced. The inner tires are easier to balance since they are not on the Alcoa rims.

Amg · 09-15-2017, 09:47 PM

I would like advice on the replacement tires. The two inner rear wheel tires were replaced with a brand called "Ironman". Since I had two flats and limped to a tire shop I was not in a position to shop around. The question is it if it is okay to mix a different brand with the factory tires on the unit? Thanks

Protagonist · 09-16-2017, 05:15 AM

Quote:

Originally Posted by Amg

I would like advice on the replacement tires. The two inner rear wheel tires were replaced with a brand called "Ironman". Since I had two flats and limped to a tire shop I was not in a position to shop around. The question is it if it is okay to mix a different brand with the factory tires on the unit? Thanks

I wouldn't. I'd keep all the same brand on the same axle. Even for tires with the same nominal size, there can be small differences in tire height for different brands, which would cause the taller tires (whether they're new inner or older outer duals) to carry a disproportionate percentage of the vehicle's weight.

What you can do at this point, to keep from buying even more tires, would be to dismount the inner duals and front tires, and swap them, so you have two new tires on the front and four older tires on the rear.

CapriRacer · 09-16-2017, 07:12 AM

It is especially important to keep each set of dualed tires (that is, the 2 tires paired together) the same - same make, same model, same state of wear. That way the diameters are very close to the same.

If you don't, the taller tire will be carrying more of the load - and that makes it more likely the taller tire will fail.

Amg · 09-16-2017, 07:34 AM

Thanks. What if I take one of the inner tires and make it an outer tire next to same brand inner tire. I know I will have to rebalance because of using the Alcoa wheel. Reason is when I bought coach I had diffult time balancing front tires. Now it rides great

TRIPPPIN · 09-16-2017, 08:12 AM

I had a similar problem with the internal tires on the duals going flat and it was because the valve extenders were not totally secure. These must not be able to move or flex or they will leak while they are put under centrifugal force.

Don't mix tire brands or types on the same axle no matter what. If your fronts are balanced now a good tire shop should be able to do it again.

Amg · 09-17-2017, 03:37 PM

Tireminders finally got back to me. Their communications were disrupted because of the hurricane. They indicated it was probably a problem with the installation of the tireminders on the two inner tires. I purchased the tireminders from my Airstream dealer and they installed them.

Tireminders offered to install new ones at their Stuart Florida headquarters when I come back to Florida. My thoughts now are to remove them. I purchased them to check the tires especially the inside rears, in fact they caused my flats. I always manually check my tires before each trip. That is how I found the flats. I just will follow that proceedure.

I do appreciate the advice not to mix different brands of tires. Just so I am clear, I can have different brands on the left rear tires and another brand on the right rear tires, just so that each side has the same brand. Am I correct? Thanks

RICKBETTY · 09-17-2017, 05:00 PM

100 % caused by leaking value stems. there is a metal value stem kit that can be purchased and installed for sprinter vans, I don't have the info handy, .. You can look up on this forum.. I installed on mine, and never had a problem, very easy to check pressure and and adjust pressure if needed. Also purchase a good electronic tire pressure gauge, and air compressor.

c21 · 09-18-2017, 11:48 AM

Quote:

Originally Posted by RICKBETTY

100 % caused by leaking value stems. there is a metal value stem kit that can be purchased and installed for sprinter vans, I don't have the info handy, .. You can look up on this forum.. I installed on mine, and never had a problem, very easy to check pressure and and adjust pressure if needed. Also purchase a good electronic tire pressure gauge, and air compressor.

The valve stem kits you are referring to are the Borg Dually Valves. (Model DL1SPAL for Airstream Interstates. They are available from "yourtireshopsupply.com for $120+shipping. I have used these on two rv's along with TST tire pressure sensors with never a problem.

Amg · 09-19-2017, 12:34 PM

Thanks for help. I just ordered the suggested Dually valves. I will give the tireminders another try.

Can someone just confirm it is okay to have the same brand tires on the passenger side of the rear axel and another brand on the drivers side of the rear axel . Thanks

slowmover · 09-19-2017, 06:36 PM

Quote:

Originally Posted by CapriRacer

It is especially important to keep each set of dualed tires (that is, the 2 tires paired together) the same - same make, same model, same state of wear. That way the diameters are very close to the same.

If you don't, the taller tire will be carrying more of the load - and that makes it more likely the taller tire will fail.

Semi Truck owner Joy: lose one, but buy two. No choice.

Protagonist · 09-19-2017, 06:58 PM

Quote:

Originally Posted by slowmover

Semi Truck owner Joy: lose one, but buy two. No choice.

Also, compare the "orphan" tire to the spare, and keep the better one. It would be wasteful to discard a perfectly good tire that's in better shape than your spare.

slowmover · 09-19-2017, 07:34 PM

Quote:

Originally Posted by Protagonist

Also, compare the "orphan" tire to the spare, and keep the better one. It would be wasteful to discard a perfectly good tire that's in better shape than your spare.

Generally, spares aren't carried. The fleets of any size have national accounts where this problem is factored in. A credit for the undamaged tire is issued based on condition. It's then re-sold as a trailer tire, or sent out for re-cap.

That said, in the past I've had to lash down both tires -- ruined and good-- to return to a company shop. Inspection and credits to be done with the local rep of the tire company.

Tires are the big truck expense after driver compensation and fuel. A full set of tires can be thousands of dollars.

To the OP. Tireman9 (Roger; retired tire engineer) has his own RV tire safety blog. Strong focus on motorhome tires. Worth your time from beginning to end.

CapriRacer (above) also a tire engineer, graciously adding to our threads. Also with a tire info site.

.

TRIPPPIN · 09-20-2017, 07:12 AM

If you don't like the answers you got about mixing tires on the same axle and keep asking the same question someone may eventually tell you what you want to hear and that would be a mistake. Tires that do not match will change the handling performance of the vehicle and is a safety concern. I would not mix tire brands or types on the entire vehicle but I just like to be safe when it comes to tires. FYI Capri racer is a tire authority and told you not to do it - I recommend you follow the advice at a minimum to not mix on the same axle and better still get all the tires to match.

Boxster1971 · 09-20-2017, 03:10 PM

Quote:

Originally Posted by Amg

Thanks for help. I just ordered the suggested Dually valves. I will give the tireminders another try.

Can someone just confirm it is okay to have the same brand tires on the passenger side of the rear axel and another brand on the drivers side of the rear axel . Thanks

No - It is not OK to mix tire brands on either side of an axle.

Amg · 09-20-2017, 08:59 PM

Thanks. I was not trying to ask the question again because I did not like the answer. I did not understand that "the same axle" meant all four tires not just the two on either side.

I did read the blog by tireman9 and it was quite helpful. He indicates I need to replace the two good tires that did not go flat. He said that riding even a small distance on only two tires put twice the weight on them and structurally comprised them. I plan on replacing all four tires in the rear with the same Continental tires in the front. I just don't feel comfortable taking the two new Ironman tires and putting them on the front. I never heard of Ironman tires and if I have a blowout in the front at high speed that could be a disaster. Spending several hundred dollars more will be good insurance.

Ynefel · 09-21-2017, 10:15 AM

I had installed the metal valve extenders on advice from this forum a couple years ago. One inner tire went flat on a trip this summer, and on examination at a fortunately open nearby tire shop, the original installers (my RV dealer) didn't secure the extenders properly and complete omitted the blue loctite recommended. The shop examined the the other inner valve stem and it was ready to cause another flat too.