How do I know a tire's low/flat on dual wheel axle?

TPMS or Tire Pressure Monitoring Systems will tell you the current PSI and Temperature. You can set up alerts to warn you when values get out of your set parameters.

I've felt a flat dual on a truck as an imbalance, just like a tire that was out of balance.

When stopped (fuel, break, ect) I'll reach under the fender and just push sideways on the inner tire; if it gives way it is low on air. Or you can stand behind the truck/trailer and look for a tire that has an excessive bulge when sitting on even ground.

There's this new invention called TPMS.

I am old school, still have a wooden tire thumper I purchased at a truck stop. Also comes in handy for a "just in case" . When taking a rest stop I check all around my rig and will break out the gauge if necessary.

BillHoughton wrote:
but what about more subtle flat conditions, like a nail in the tire?

You hear what sounds like an explosion.....as the tread comes off and damages body parts....and maybe electrical wires and water lines too.

I find that an electronic "Tire Minder" gives me a LOT of piece of mind. And just one "use" might save you enough to pay for it.

After driving you can check the temperature of the tires with your hand (carefully) or with a laser IR thermometer. A low tire will typically be warmer than the others, though some differences in temperature are normal and expected. (The inners are often a bit warmer as they have less cooling airflow, and the right inner on my motorhome is also warmer because it's closest to the exhaust system).

If you check the pressure before each day of travel, you'll be well ahead of many people already.

I have a TPMS with sensors on my trailer and on my dually truck. I had a flat on the inner tire and only knew about it because of the monitor. It did not happen while I was traveling but I got an alarm as soon as I started to move the truck. I could not tell by looking that it was flat. I use the system even when not pulling the trailer for that exact reason.

I put cat eyes on my duallies. Whenever I stop, I do a visual check of the cat eyes to make sure everything is still good.

PenMan wrote:
I have a TPMS with sensors on my trailer and on my dually truck. I had a flat on the inner tire and only knew about it because of the monitor. It did not happen while I was traveling but I got an alarm as soon as I started to move the truck. I could not tell by looking that it was flat. I use the system even when not pulling the trailer for that exact reason.

What TPMS system did you add to your truck ? I have a 2005 dodge dually I'd like to put TPMS on.