Slow Air Leak

[five]

Today I noticed my inner dually, street side was down to 60 lbs.  Long story short, in adding air, and removing the tire pressure sensor and checking the TP, several times, the four inch valve extender unscrewed when I was trying to unscrew the TP sensor.  So, I'm thinking the four inch extender has been a bit loose, resulting in the slow leak.  I put a socket on the extender and tightened it...as well as the one on the other side....so far no leaks.

What think you guys?

[wolfe10]

The valve stem/stem extension is certainly a likely source of an air leak.

Soap bubbles will hep identify that-- blowing bubbles is BAD.

[hermanmullins]

I have extender on all four tiers on the rear. They work well when installed properly and secured so as they won't flop around.

Glad you caught it and didn't have an issue on the road.

Herman

[wildebill308]

I would use a drop of Loctite Blue (removable grade) to keep them from coming loose. 

Like Brett said test for leaks. 

Bill

[manholt]

"Blowing bubbles is BAD"...  

[tireman9]

On 6/10/2018 at 6:44 PM, FIVE said:

Today I noticed my inner dually, street side was down to 60 lbs.  Long story short, in adding air, and removing the tire pressure sensor and checking the TP, several times, the four inch valve extender unscrewed when I was trying to unscrew the TP sensor.  So, I'm thinking the four inch extender has been a bit loose, resulting in the slow leak.  I put a socket on the extender and tightened it...as well as the one on the other side....so far no leaks.

What think you guys?

Wondering why you were removing the TPM sensor to "check" the inflation. Also how the inflation got down to 60 without the TPM sounding off.

In my RVTire blog, I have a number of posts on tests for accuracy of various TPM sensors and have found the dozen sensors I tested, to be acceptable. So the only time I would have a sensor off is when doing the initial pressure setting and maybe a couple of times a year like in late Fall and Early Spring when there are large changes in temperature.

Different TPMS have different settings for the low-pressure warning level but I suggest the low-pressure level should be set at the minimum inflation needed to support the measured tire load. You will need to read your system instructions and maybe do a little calculating but you should be able to do it.

One of the reasons I suggest the CIP be set to your minimum +10% is that will give you margin so the day to day effect on tire pressure due to temperature change should mean you don't need to. With pressure changing 2% with a change of 10F you would need a 50F drop before you would need to add any air.  Since tires can tolerate both temperature and pressure rise you don't have to "chase your tail" every day messing with tire pressure even when the temperature rises 30 to 50F

[jleamont]

Five, we have a policy at work, Operating pressure is 110 on 98% of the fleet, for this application (similar application to you) if a tire is discovered below 75 psi it must be pulled and sent out for x-ray.

Before Michelin came out and trained everyone we would often have staff attempt to add air to a tire and it would almost always explode immediately or shortly after within in a few miles. Id have that taken to a professional truck tire center, have them inspect it at a minimum. You don't want it cutting loose on the road, I don't know what you typically run in PSI, but 60 is quite low for a commercial tire like your coach utilizes, id be surprised if it didn't damage the tire.