Originally Posted by otorvund
I have now installed TPMS TireMinder on my trailer tires. I have always set my tires to 80 psi before leaving on trips which is according to the manual. Now we see that the pressure goes up to 94 sometimes when we drive - especially in hot weather.
Is that OK - or should I bleed the tires a bit to get closer to 80?
On the tires it states that Max PSI = 80.
Tire type is Goodyear Endurance ST
No, do NOT EVER bleed down a hot tire. Wait until it has cooled before you approach it. (takes an hour and a half.)
Second, tires are designed for pressure buildup. Their burst pressure is several times the max pressure. The max pressures listed are for COLD tires (that is, tires that haven't been operated for a couple of hours.) Hot tires will have higher operating pressures - and that's by design.
Further, you may be experiencing normal pressure buildup. Allow me to explain.
Yes, the rule of thumb says that you shouldn't get more than a 10% pressure buildup - discounting the ambient temperature affects. If you do, you need to plan to fix that by getting more load carrying capacity or slowing down.
If you experience more than 15%, you need to fix this immediately - first step being slowing down, followed by more load carrying capacity as soon as possible (within a day).
Ambient temperature affects? Tire pressure will increase 3% for every 10°F rise in ambient temperature.
So while you are reporting a 17 1/2 % pressure buildup, most of that could be due to the increase in outside air temperature.