Tire Pressure Monitoring HELP Please!

[Carl]

Just rotated tires on 2010 SMB. Had local garage do the work and everything appeared fine. adjusted pressure to 60 front, 70 in rear and 70psi in spare as well.

day later noticed drivers rear seemed low?

spent an hour looking for leak, water/soap, etc.... with no luck?

Any known tire pressure monitoring system things that could cause this?

Any ideas?

thanks,

carl

[Carl]

just went back at it today, took tire off, spent an hour with spray bottle of soap and water, did entire tire, found nothing! Nitto Terra Grapplers with 6k, like new, no cuts, and other than a few small rocks in siping, nothing! any ideas?

thinking a tire shop can put in water tank.

[yvrr]

There isn't anything which is part of the tire monitoring system which would cause a leak. Air temperature changes can change the tire pressure and things like the van sitting on a sloped driveway can cause the rear tires to look low but the pressure won't change.

Did it just look low or was it really low? Did you check it yourself? How low was it?

[Carl]

checked again with soap and water, nothing. also sprayed valve stem good and bent it, nothing?

set pressure today at 80 psi, and in about 4 hours it is at 65.

obviously a leak somewhere, but I assume a garage with large water tank can pump it up and test it better than I did today.

[Steve_382]

Have you checked the rim for leaks. I had an aluminum rim years ago that had a leak through the metal. I took a center punch and hammer and sealed the leak until getting a new rim. Just a thought.

[yfarm]

I recently has a valve stem on a schrader TPMS crack lengthwise where the seal and nut cover the stem, one day it was fine,the next started to leak with no trauma to the stem.

[Carl]

figured it out today! Moto Metal 18" rims. Sure enough, put in a tub of water and it was the back side of the rim itself in middle where spokes join the rim. small pin hole.