My RV Tires Were Fine This Morning. What About 200 Miles From Now?

Why We Added the TST 507 TPMS to Our Fifth Wheel

By: Mark Brown – RVD Contributor

I’ve always paid attention to tires. Before we leave on a trip, I check the tires on our truck and fifth wheel when they’re cold. I look at pressure, inspect the tread and sidewalls and make sure there’s nothing obviously wrong. I also check them again during longer trips.

I thought that was a reasonably good system until a few years ago when my wife Jen and I were traveling on I-75 with our fifth wheel.

We had been on the road for a couple of hours when a car pulled alongside us. The passenger kept pointing toward the back of our trailer and trying to get my attention. I slowed down, found a safe place to pull over and walked back to see what they had noticed.

One of the trailer tires had lost a significant amount of pressure and was beginning to come apart. We caught it in time. There was no major damage to our fifth wheel, and nobody was hurt, but neither of those things was the part that bothered me most. What bothered me was that I had no idea it was happening.

I’d checked that tire before we left. It was properly inflated then. Two hundred miles later, that information was no longer particularly useful.

That’s when I decided there had to be a better way. After much research, I learned about the TST 507 Tire Pressure Monitoring System and quickly installed it before our next trip.

A TPMS doesn’t prevent tire failures, and I think that’s an important distinction. I still inspect our tires, check pressures before a trip and pay attention to tire age, condition and load. The TST system doesn’t replace any of that. What it gives me is information I couldn’t previously see while we’re moving.

The 507 uses sensors at each monitored tire to transmit pressure and temperature information to a display in the truck. Instead of only knowing what my tire pressure was when we left the campground that morning, I can see what’s happening while we’re traveling. The system can be programmed with high and low pressure thresholds and a high-temperature threshold, and it can alert the driver to a rapid pressure loss.

For me, that’s the value of the system. A tire gradually losing pressure may not produce anything I can feel through the truck, particularly when it’s several dozen feet behind me under a fifth wheel. Temperature information can be useful as well. If one wheel is behaving differently from the others, that’s information I want to have.

The TPMS isn’t diagnosing the problem for me. It’s giving me a reason to pull over somewhere safe and find out what’s happening.

TST offers several sensor configurations, including cap, flow-through and internal sensors. Cap sensors thread onto the valve stems and can be used with rubber or metal stems. Flow-through sensors let you add air without removing the sensor, but TST specifies metal valve stems for those. The current cap and flow-through sensors use replaceable batteries.

Each sensor is paired with a wheel position on the monitor so I know exactly which tire I’m looking at. The display cycles through the monitored tires and shows pressure and temperature. If the system detects an abnormal condition, I don’t have to guess which tire triggered the warning.

The system also uses a signal repeater, which is important with a longer RV. The repeater mounts on the trailer, connects to a 12-volt source and helps strengthen the signal between the sensors at the trailer tires and the monitor inside the tow vehicle. TST currently includes a repeater with its aftermarket kits.

Installation isn’t particularly complicated, but setting the system up correctly matters. I took the time to identify each sensor by wheel position and set the appropriate alarm parameters rather than simply installing the hardware and assuming the default settings were right for our fifth wheel. That’s something I’d recommend doing with your tire specifications and RV information in front of you.

I’ve heard people describe a TPMS as insurance against a blowout, but I don’t look at it that way. It can’t prevent a tire from picking up a screw or being damaged by road debris. It can’t prevent every tire failure, and a catastrophic failure can happen too quickly for any warning system to give you much time to react.

What it can do is give me a chance to see certain problems developing before they reach that point.

If a tire begins losing pressure while we’re traveling, I want to know about it before somebody in the next lane has to tell me. If one tire is running unusually hot compared with the others, I want that information while I still have an opportunity to find a safe place to stop and determine why.

I still start travel days the same way I always did. I inspect the tires and make sure they’re properly inflated before we leave. The difference is that now my information doesn’t stop the moment I put the pressure gauge back in the toolbox.

A stranger in another vehicle had to tell me something was going wrong with our fifth wheel the first time. I’d rather have the monitor tell me next time.