FYI On a recent trip a Valve stem on the tow failed

[Joe Hogan]

Thank goodness for a TPMS. Pulling out of a campground the TPMS alarmed sounded. A quick check indicated low pressure on the passenger rear tire of the Passat in tow.
Stopped at the next exit and checked tire pressure with a gauge. Sure enough 17 psi vs expected 38 psi.
Stopped at a local tire shop. this shop indicated no puncture, so good to go....NOT.
Drove the day without the TPMS attached thinking that that something to do with the leak.
Checked tire before next departure, pressure down to 28 psi??
Now I started examining the tire and valve myself.
Found that the stem when pushed to the side leaked, a small crack in the base at the wheel.
Stopped at a different tire shop explained the issue, and had it repaired.

Next step is to replace all valve stems with metal clamp in style valve stems.

Cause? not sure: if the TPMS weight caused this issue, or a stone hit the valve stem. The valve stem is not more than a month old. Tires on rear of car were replaced last month with new stems.

BTW, did you know that rubber valve stems are rated for only 45psi? Typically I run 38 psi cold, but on a hot day, and full load that psi can escalate to close to 45 psi or above. In Death Valley tire temps got scary high.
These new rear tires have a maximum psi of 55 psi for max load.

Clamp in stems are typically rated for 130 psi.

 

[Neal]

I had a slow leak in right tag tire, it ended up being a failed o-ring in the TPMS sensor itself. It can be anything.

 

[Texas Clodhopper]

Several TPMS suppliers recommend using metal valve stems.

 

[sheridany]

I have been researching this as I have read that having metal valve stems is better for the sensors used by a tpms. How do metal valve stems work if the toad has a tpms on the vehicle?

 

[Kevin D Pem]

I have been researching this as I have read that having metal valve stems is better for the sensors used by a tpms. How do metal valve stems work if the toad has a tpms on the vehicle?

look to this site for information on your stems.

Tire Valve Stem Replacements - TPMS Valve Stems

Need a TPMS valve stem replacement? Browse our selection of valve stems that are compatible with factory & aftermarket TPMS systems. Enjoy FAST shipping on most orders!

www.tpms.com

 

[Joe Hogan]

On the VW the OEM TPMS system does not use sensors. The VW system uses differential wheel speed to sense low tire pressure. Unfortunately I have had many flat tires on this vehicle and the TPMS system works flawlessly.
On the RV I use the EEZ TPMS system. EEZ uses screw on tire sensors. So the Passat has an OEM system when driving the vehicle and screw on sensors for the EEZ TPMS when towing.