Valve Stem Leak - Not Core

[RamFan]

I've noticed for about 2 weeks now that the rear passenger tire has been leaking 2-3lbs a day. Finally got time to take a good look at it and instantly diagnosed it coming from the valve stem. I've had cores leak in the past, but this isn't coming from the core, or at least it doesn't appear to be. What's the best recourse for repair?

If you look closely in the video below, between the core wall and the hex of the valve assembly, you can see the bubbles coming out.

 

[FordBroncoVWJeta]

I would make sure it is tight, by torquing down the sensor. If it is tight, probably a bad O-Ring.

 

[atikovi]

No warranty?

 

[RamFan]

Originally Posted by atikovi
No warranty?


Yes, however the service dept. is open during business hours, no weekends. So if it's simply swapping the core or torquing the stem I'll just take care of it.

 

[FordBroncoVWJeta]

Originally Posted by RamFan
Originally Posted by atikovi
No warranty?


Yes, however the service dept. is open during business hours, no weekends. So if it's simply swapping the core or torquing the stem I'll just take care of it.

Thats not going to be a core malfunction, the core won't leak there. Either its not torqued down or the orings are not working correctly. If its the oring problem let them mess with it. You're going to have to debead it, tear down the TPMS, and have the correct kit to do it.

 

[RamFan]

Originally Posted by FordBroncoVWJeta
Originally Posted by RamFan
Originally Posted by atikovi
No warranty?


Yes, however the service dept. is open during business hours, no weekends. So if it's simply swapping the core or torquing the stem I'll just take care of it.

Thats not going to be a core malfunction, the core won't leak there. Either its not torqued down or the orings are not working correctly. If its the oring problem let them mess with it. You're going to have to debead it, tear down the TPMS, and have the correct kit to do it.


After seeing your first comment, I checked the valve and it's definitely tight. The leak slows when pressure is applied to the stem, take the wrench off and it leaks more. I think you're right with it being the o-ring.

 

[geeman789]

Careful with just tightening it down. Some TPMS valves have a VERY low torque spec, and they will break. You need a rebuild kit, which is pretty much just the o-ring, a new valve core and a base with washer.

 

[mattwithcats]

Service Kit

https://www.rockauto.com/en/catalog/alfa+romeo,2018,giulia,2.0l+l4+turbocharged,3437232,wheel,tire+pressure+monitoring+system+(tpms)+service+kit,12037

 

[RamFan]

Originally Posted by geeman789
Careful with just tightening it down. Some TPMS valves have a VERY low torque spec, and they will break. You need a rebuild kit, which is pretty much just the o-ring, a new valve core and a base with washer.


Absolutely, I know how delicate these TPMS valves can be. Swung by the dealership this morning and confirmed the cause, have an appointment next week for the warranty repair. SA stated that they often find cracks at the base of the valves on these.