Tire pressure monitor systems

We have a tire minder system on truck and TT. On our latest trip it saved me some serious cash and possibly saved our trip. The right rear sensor on the truck started reading a high temp going across Kansas. I pulled over to check the temps with my infrared temp gun and found that the emergency brake drum was getting REAL hot. I crawled under the truck and found that my emergency brake had hung up and was in the process of cooking my brake, and grease seal on the differential. Without the warning, I would have probably had a rear end failure that would have probably ended our trip and cost me BIG money in repairs. I have not had any leaks on the rear end so I hope we caught it in time.