Making longer, easy-to-grip valve stem caps

I had found reaching into the trim ring to remove the valve stem caps to check tire pressures was awkward as the caps did not stick out far enough to get an easy grip. Metal valve stem extenders corrode onto the brass threads of the valve stem, and plastic valve stem extenders do not have threads for a protective cap. So I purchased longer valve stem caps from Dorman, but found that they only had threads at the very top of the longer cap and thus could not be screwed down onto the shorter valve stem of our 2012 Prius.
The fix was to take the Dorman long caps and grind out the lower section with a Dremel tool using a small, conical grindstone attachment.




Next I sandpapered the top of a normal valve stem cap into a conical shape, applied expoxy glue to the top and clamped it into the longer Dorman valve stem cap.


The result is a valve stem cap that correctly and securely fits on the Prius valve stem, but is easy to grip and remove when you want to check tire pressures.