...fate. It was pretty cold this morning, and shortly after I started the pathfinder the TPMS went off... I rarely stop on the front side of my commute so I reserved this for after work. The last cold day triggered this event as well, but when I went to fill the tires, the caps wouldn't budge. I put some pliers in the back for when this happened again, or I was at the free air station. So today was the day, I stopped by the station while on my way home from work, and I attempted to gently remove the cap by hand, and as expected it would not budge... I grabbed the pliers and ever so slightly tried to turn that cap to no avail, I then increased the amount of force minutely, and (insert drum roll here) the tip of the stem, cap, and valve came off in the jaws of the pliers! After about 15 seconds of listening to the air escape as my truck slowly slouched... I just stared at it dumbfoundedly while this happened. It was rush hour so calling the autoclub would have been a 3 hr wait minimum... So, I changed the flat and proceeded to NTB (only about a block away mind you). Both front tires had seized caps, but rather than try that again since I only have one spare and I wanted to see how much my error was going to cost me... I took the short drive.
Lesson learned no aftermarket chrome caps for me ever again. I bought the damn things after losing one cap somewhere somehow from Advance Auto. As a chemist, not an electrochemist though, the basis for what happened is the two different metal alloys created a galvanic electrochemical cell at their interface and over time the cap basically welded itself to the stem. Thankfully two of my TPMSs were salvageable. I needed to buy tires anyway, but I wasn't planning to do it today. /VENT