Shredding of the red o-rings in TPMS sensors

My smart TPMS system has been working well for 6 months now but every time I remove a TPMS sensor from my wheels to adjust the air pressure (or, for example, when moving the sensors to the correct wheel after rotating my tires) a sliver of the red O-rings that seal the sensor to the valve stem shreds away and must be removed using a tweezers to keep the sensor’s threads and workings clear of debris.

The material used in these red o-rings seals appears to seal well but doesn’t hold up to repeated removal and re-installation of the sensor. Nonda should provide extra and/or replacement red o-rings for the TPMS or find a tougher material. I expect that eventually these red o-rings will fail due to continual shredding.

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Same here, I rarely take sensors off but when I do I see small threads of the red O-ring. However I don’t think they let the air out.

is it possible to buy replacement O-rings? I need 4 black O-rings for the outer cap and would like to replace the inner pink O-rings too.

Hello @Vv_Kk
Feel free to send your request to I’m sure they offer such replacement. Users might have to pay for the deliveries and etc.
Best Regards,

I asked for a replacement and received this reply: “Unfortunately, the small parts are not replaceable. You will need a new sensor if there’s a missing piece.”

Yes, their CS team is useless.

Does anyone know what the spec size is for the small red O-rings? or know if the sensor is replaced without the O-ring, will it result in a small leak?


I do not know the spec for the o rings, but there will be more than a small leak without them. i filled up a tire the other day and took off the sensor. the o ring fell out and i didnt notice; the tire went completely flat sitting overnight :confused:

which is completely silly - “this $.50 peice failed, go ahead and buy a whole new sensor”