View Full Version : Tire Mystery!

10-22-2015, 01:54 PM
OK, here's the story. When I had my Goodyear Marathons on my RV I noticed a strange thing happening; the front right (passenger) tire would deflate from 80 psi about 40 or 50 psi when it sat for an extended period of time in my driveway. By extended period of time, I mean just a couple of months.

At one point, I had the tire removed and checked by a service facility and they could find no problem. The tire functioned well ('well' being a relative term, since it was a Marathon tire) other then for that anomaly. We also noticed that when we drove to Florida it did not seem to lose pressure like it did at home.

Now that I have upgraded to the G series tires, I figured that problem probably would disappear. But the same positioned tire is doing the same thing, this time going from 110 psi to about 80 psi.

Do any of you tire wizards have an answer for this? For the record, my RV sits in a driveway that is tilted at a slight downward decline. None of the other tires seem to lose pressure in any significant way.

10-22-2015, 02:01 PM
Is the subject tire mounted on the same wheel that the other problem tire was??
If so I would suspect that wheel!

10-22-2015, 02:06 PM
Spray the rim with soap and see if it bubbles anywhere. Sounds like a faulty rim.

10-22-2015, 02:11 PM
Or loose valve stem.

10-22-2015, 02:54 PM
We actually had a rim on our new SOB that had a tiny pin hole. Tire shop had to pump up to 150 Lbs (125 PSI tire) and dunk the assembly to fine the pin hole. New wheel solved the problem.

10-22-2015, 03:06 PM
I had a similar problem with a very slow leak. Finally discovered small crack in rim, replaced under warranty, no more leak. Commercial truck tire company finally discovered the leak by submerging whole tire at 110 psi , very few bubbles so not easy to see at first.

10-23-2015, 01:12 AM
That would be my guess also. If the new tire is mounted on the same rim, there has to be a tiny defect.

10-23-2015, 01:55 PM
Probable bad rim or bad valve stem.

11-25-2015, 03:19 AM
So, I had originally reported this defect to my RV seller when I bought the rig about two years ago and Marathon tires were on it. Since I have put the G614 tires on it and discovered the leak still exists, I brought it back to my dealer. They state they cannot find any leak and they will not replace the rim. When I explained to them they had only had the rig for five days, they stated I would have to leave it longer. I'm willing to do that andI told them and then they said they didn't want it sitting on their lot for two months.

Catch 22 I guess, they don't want to leave it on their lot and I'm letting them know that it will take two months or so for the 20 or 30 pounds to dissipate. I am not happy with them and we are in the process of discussing it.

11-25-2015, 04:00 AM
Agree, rim or valve although I would have thought new valve stems with the new tires.

11-25-2015, 04:16 AM
I would also suspect stem or rim. But based on the fact that it did not drop air pulling to Florida makes me wonder. You would think that if the rim had a defect or pin hole it would have to drop air while towing because the pressure builds when rolling down the road. If it was a bad stem I would think the same thing, it would be more pronounced while towing.

Are you sure some kid or neighbor isn't jacking with you while it is parked at home?

11-25-2015, 04:23 AM
Just take that wheel/tire to a competent tire dealer that has the equipment to find the issue. Find out where the wheel was sourced from and present your case to them. If the won't replace it with evidence from a tire dealer and your case facts, then buy a new wheel and live happy. Certainly not worth dragging the Montana to the dealer, not worth extra stress in the life, not worth the time stolen from more important things in life. John

11-25-2015, 06:23 AM
Some times those type of problems require exceeding the normal tire pressure, such as putting 150 Lbs in it and dunking into a tank of water. We went through a similar issue with our newest SOB in April. Found a very very small pin hole in the wheel casting.

11-25-2015, 06:55 AM
Believe it or not air can escape through solid steel. If you cut a piece off of a round steel bar and wield it in a piece of pipe it will leak. At one time I did a lot of work for the electron tube industry. They build these tubes and pull a near perfect vacuums on them. A fingerprint will take several days to draw off. If the steel isn't cut right the tube will never hold a vacuum. It may take several days to a month but it will go to air and a $50,000 tube is scrap.

12-03-2015, 02:25 PM
Tredit is the source for Montana's wheels. I would first have a good tire shop determine if it's wheel or valve stem. If it's the wheel, contact Tredit or Team Montana.

12-04-2015, 02:39 AM
Try the easiest thing first. Changing the Valve stem is easy. All thing the same, at then it must be that which is left, the rim.

12-07-2015, 06:08 AM
had the same problem with my 2008 Everest, it was a crack in the wheel on the inside middle. out of warrenty from keystone , but a few phone calls and the right person and I got a new wheel . they sent it to my dealer and it was all taken care of with no charge. good luck, and happy holidays

12-09-2015, 04:59 AM
I have had the same problem on a auto. It would only leak when parked for some days. If used daily it would not leak even 1 oz. If I were you I would dismount the tire and clean the sealing surface with a wire brush Both tire and wheel. But you could have it completely submerged in a tank to look for bubbles. I am assuming this is the same wheel not just the same position with the Marathons and the G614's.

12-27-2015, 03:56 PM
Question for all of you. When changing from E to G tires, and the additional pressure the G's can rate, what is the maximum pressure the stock Montana aluminum wheels can take, up to 110, less or more?

12-28-2015, 04:38 AM
Maximum psi should be stamped on the back of the wheel. I believe all the later model Montana's came with 110 psi rated wheels.

12-28-2015, 05:00 AM
There seem to be a lot of different opinions on this and some are based on actual weight measurements made by folks. Since this isn't something I plan on doing, I'm thinking I will run the GS 614 tires at about 95 pounds per tire.

12-28-2015, 05:08 AM
Oh, sorry. I see you were asking about the wheel capacity and not the actual psi.

12-28-2015, 05:30 AM
If you run the G614 tire at 95 psi, the load capacity will be 3415 lbs per tire, which will not quite make the most of your 7,000 lb axle. The Goodyear inflation chart is available at http://www.goodyearrvtires.com/tire-inflation-loading.aspx

You go to Tire Inflation& Loading, and there is a button that will take you to the charts. When you find the LT235/85R16, follow the chart to the right where you get to the G range pressures. At 110 psi, the tire is rated the full 3750 lbs capacity.

12-28-2015, 06:14 AM
So Bob, do you run your tires at the full 110 PSI?

12-28-2015, 07:43 AM
Yes I do, or try to. As long as I am at least 100 psi cold in the morning, I'm good, but generally I try to keep it pretty close to 110 psi. When you are at those pressures, a few pounds isn't going to make much difference in ride or handling, which is much better than with the Marathons this rig came with.

12-31-2015, 03:16 AM
quote:Originally posted by rohrmann

Yes I do, or try to. As long as I am at least 100 psi cold in the morning, I'm good, but generally I try to keep it pretty close to 110 psi. When you are at those pressures, a few pounds isn't going to make much difference in ride or handling, which is much better than with the Marathons this rig came with.

Thanks Bob, I found the max pressure of 110psi stamped on the wheels, I agree with you that running cold at 100 in the morning is a good idea. Thanks for the follow up on this question.