I have owned my Goldwing for five years now. I’m on my fifth set of tires and the thought occurred to me about the TPMS valves. Do they ever need to be serviced? There must be an Oring or something that seals the stem. Does anyone have any advice or information about this. I would appreciate all comments. Thanks.

I assume the TPMS warning light showing batteries failed or throw a code to display an engine trouble light. New TPMS's will need purchasing at some jaw dropping cost 4-500 parts and labor to replace. There are videos on how to replace the batteries if you can remove them and are comfortable desoldering and resoldering to remove and replace batteries.
The older Goldwings had a hack to null the warning lights. I've now seen a similar hack for the 2018 plus system. If there was one could install FOBO sensors and save oneself several hundred dollars. I carry a new OWM valve stem just in case if a rubber grommet leak. Great question as I've nor seen any posts on failures and cost of this failure. 😎

I believe you could just leave the dead sensors and stem intact and use FOBO screw on sensors or you likely could remove failed TPMS transmitters and leave replacement stems. However the warning light would remain on at the dash. Since there is no 18plus tack to bypass the warns light some have placed a smilee sticker to cover it. Has any one sourced another less expensive TPMS sensor for the 18 plus Goldwing? It's a go to the hip OEM bite the bullet solution going OEM 😩