Wonky TPMS / PSI Readings

[Trailman]

Hi all,

I have onboard air (double ARB mounted on Kraken system). After airing down and then airing back up, I get wonky PSI readings. Let's assume I air down to 17, then air up to 37. After letting things settle during the air-up at a consistent 37 across the four tires, I drive off.

For the next several weeks, my tire pressures will bounce around from 27 to 35. Usually when I start they are very low, and then will gradually work back to 34 or 35 across the four tires. Cold weather and weather change are not the issue, as I'm discussing warm summer trips.

Note that this does NOT happen after an oil change/tire rotation. The dealer will usually fill to a very high 40 or 42 psi. But, I see very little fluctuation after a dealer air-up. This only happens after I do onboard air.

Any ideas? Is this a normal thing? It happens consistently with air ups I do after finishing a trail.

Sponsored

 

[Kevin_D]

Tire temperature, fill-air temperature & humidity will affect pressure & readings.
Your on-board compressor is pumping through whatever is outside the truck, and increasing the fill-air temperature.
The dealer is using a very large compressor, which doesn't raise the fill-air temperature much, and probably a line dryer & cooler, which provides conditioned air for fills, running air tools, cleaning, etc.
Get a known-good pressure gauge, and use it to compare with your TPMS readings. You could find that your tire pressures are indeed varying.

Kevin

 

[jav_eee]

Tire temperature, fill-air temperature & humidity will affect pressure & readings.
Your on-board compressor is pumping through whatever is outside the truck, and increasing the fill-air temperature.
The dealer is using a very large compressor, which doesn't raise the fill-air temperature much, and probably a line dryer & cooler, which provides conditioned air for fills, running air tools, cleaning, etc.
Get a known-good pressure gauge, and use it to compare with your TPMS readings. You could find that your tire pressures are indeed varying.

Kevin

this guy has the answer.

Sponsored