I got this tire that is bugging the crap out of me

Might just be a bad valve stem core. Regardless, some minor breaches will only lose down to a certain point, then will hold. But the leak can be found if one is serious about it and wants to deal with it and/or spend the money to get it looked at, one way or another.

 

If it's holds 90 I wouldn't worry about it. That's pretty strange though.

 

Weird problem, but like others, I would imagine a bad valve-stem. Have a REALLY close look at it your next pre-trip as we are in Blitz-Week and I can pretty much promise you the DOT WILL.

 

air it up, put a little water on the valve stem to see if it leaks

 

I had this problem with a tire on my personal truck after I had new tires put on. I'd air it up to 77 psi and every day it would drop to 64 and wouldn't get any lower. The Windex trick revealed it was the valve stem. I never really got a straight answer from my tire guy as to why it would get to a certain point and stop other than "They just do that sometimes."

 

Probably that was the straightest answer he had for you.

 

If it takes 90 psi to force air through a defective bead seal/valve stem/pinhole/etc..., it will stop leaking when it reaches that point. That is until, of course, whatever the problem is happens to get worse and not as much pressure is needed to force air through the defect.

Now with 90 psi being where it settles in at, I wouldn't be too concerned...yet. Many companies only inflate their tires to 90-95 psi, and still well above the 50% of the maximum pressure stamped on the sidewall of the tire that the DOT uses to declare a tire to be "flat" or "underinflated". With the blitz coming (and the advertized focus being on tires), I'd be inclined to either put my foot down and demand a different tire that ISN'T leaking down, or just deflate the other drive tires to 90 psi so that when the DOT checks 'em, they are all the same so it APPEARS nothing is out of the ordinary. If everything is at 105 except the 1 tire @ 90, they may look more closely at that tire even though it is still properly inflated. All @ 90, nothing grabs their attention.

 

Dear A,

AIR the Tire Up, SOAPY WATER on the Spot YOU SUSPECT of LEAKING...
Find the Leak.
WRITE IT UP, ON YOUR MVI IN/ON YOUR LOG BOOK/ELD.... EVERY DAY UNTIL YOUR COMPANY FIXES IT...

C.Y.A. They Obviously Don't Care About You or their Equipment....

 

If you can't get it fixed try this, Put the Lime in the Coconut and shake it all up.