A blow out when driving a car can be scary... a blow out when driving a RV can be downright dangerous. Thing is, RVs by nature sit most of the time, and each time you take a trip, the tires may not necessarily be up to the task.
Not only do you have to remember to top off the tires to the correct pressure before leaving town, you must ensure that dry rot (a common issue with RVs) is not compromising your tires... and your safety. And if that were not enough, you can always have a blow out due to a road hazard. At minimum, A TPMS will minimize the delay in getting to the campground to start your camping fun (due to being more prepaired for unforseen tire-related events).
I once read where blow outs were a significant cause of RV accidents. So given the risk, a Tire Pressure Monitoring System (TPMS) would seem to be an essential safety item on your RV.
Especially if you have dual rear tires, you cannot always easily see what the condition of the inner tire is, or even if it is flat...
Finally, when towing a trailer or vehicle, you cannot always tell "by feel" if there is anything going on way back there, so monitoring those tires is a good idea as well.
Aside from the obvous safety issues, tires that are properly inflated return money in your pocket book by lasting longer and providing better gas mileage. A TPMS system in that regard is sure to pay for itself.
The tire pressure monitoring system I have selected is the TPMS 515 system by EEZ RV Products. This is one of many similar systems on the market, but I chose this particular system due to it's larger monitor, and the mounting options of the monitor.
TPMS 515 features:
The fast-leak feature will warn you of an impending catastrophic event, such as a blow out. Those few seconds of warning might mean the blow out will occur at 25Mph rather than 55mph.
You have your choice of two different kinds of sensor with the TPMS 515... the original sensor, as well as a "flow-through" type sensor, which basically means you can fill your tires with air without removing the sensor. The cost of either sensor type is the same, but I went with the originals as they seem to be a little bit smaller.
Installation was simple, although the manual was a bit confusing at times. Basically, setup consists of two parts. The first part is to setup the sensor for English or Metric (PSI or BAR, ° F or ° C). Next, you set the over pressure and low pressure limits (the manufacturer recommends 20% over pressure and 10% low pressure), and finally the temperature.
The second part of the installation is to "map" the individual sensors to the tire positions on the monitor. Here is where the manual seems to be confusing, so you may want to view the installation video below to clarify.
Basically each sensor has a 6 digit Hex code that identifies the sensor. Any you map that code to the desired tire position. Then, as long as you ensure each sensor remains at that position, the system will display correctly.
For example, when it is time to rotate your tires, remove the sensors, rotate the tires to the desired positions, then replace the sensors in the same "position" (not tire) it previously occupied. In that regard, the sensors are position - not tire oriented.
My particular sensors must be "air activated" to program (the batteries last for 3yrs or more). Rather than following the suggestion of doing each tire in order, I "cheated" and programmed all of the sensors using a bicycle tire. As long as I ensured the sensor went onto the RV in the tire position I programmed into the monitor, everything worked out.
When installing the sensors, I found I had to remove the hub caps. I used one of my favorite tools to do this - the JEGs hub cap tool shown here. If you are going to have a RV (with hub caps), you should buy one of these tools.
I ended up installing the sensors for the dual tires without the theft-proof caps. If you do this, the manufacturer recommends siliconing the sensors for waterproofness. Silicone the sensor at the body threads, not at the valve stem.
The manufacturer also recommends using a small amount of anti-seize compound as the sensors may be a dis-similar metal, which I also did.
For the front tires, I did use the anti-theft caps as the sensors are more exposed, are not as "tightly fitting" in the wheels, and could use a bit more protection (anti-theft as well as exposure to the elements).
Still though, I needed to remove the hub caps to install the sensors.
You get two tools to remove the sensors, but in my case, with the hub caps removed, it is possible to get a wrench into the back side of the sensor to remove it, so the anti-theft property of the sensors is not all that assured. Still, I have not really heard of anyone having the sensors stolen (they will only work with a specific brand monitor).
With all of the sensors installed, it can take up to about 10 minutes for each sensor to display on the unit. And I did notice that all of my tires were a bit low - 1 to 2 lbs. I just topped the tires off a week ago, but perhaps there is some variation in the accuracy between the TPMS and my tire pressure gauge.
The manufacturer indicates a +/- 1.5lb accuracy. It may also be likely that the slight loss of air when installing the sensors may account for that bit of pressure loss.
The TPMS is sure to be a great addition to the RV's operational safety... and it is pretty cool as well. The system has a 3yr warranty, and the sensor batteries should last for 3yrs or more.
In retrospect, I should have probably ordered the flow-through sensors, at least for the front and rear-inner tires, as they are readily accessable with a tire gauge. The front dual tires are a bit harder though, so the original sensors would be more appropriate for those.
However the manufacturer also offers inexpensive valve stem extensions that more or less convert the anti-theft type sensors to flow-through, so I may try a set of those.
Apparently it is common for one brand monitor to not have the capability of monitoring a different brand's sensors. This is due to the different frequencies used by different manufacturers. Therefore, you cannot read the OEM TPMS sensors on your towed or trailer (if you have one), even if it has a TPMS system. However, you can add EEZ RV sensors to a towed vehicle, even if there is already a TPMS system on that vehicle.
So my plan is to buy the flow-through sensors when we buy a tow vehicle, and use those for the RV, and using the replaced original sensors on the towed vehicle.
Finally, if you are towing a vehicle or trailer, you may find the distance is too great for the monitor to receive the signal from the sensor. In that case, you can buy a repeater that installs at the rear of your motor home that will effectively extend the sensor range.
I need to mention the case again. The attachment point for the arm (the part of the suction cup mount that attaches to the case) does not seem to want to fully slide in. There is a small flat of plastic preventing this.
Consequently, the fit of this arm is somewhat sloppy... and one time while handling the monitor, it flew off the mounting arm and on to the concrete floor of my garage. I thought the $300 system was a goner, but luckily it did not break.
My TPMS monitor on it's way to the floor after falling off the plastic mount.
(click photo to view video)
I would suggest if you use the mounting arm for the suction cup (either with the suction cup mount or the metal holder, then either file down the flat piece of plastic, and/or glue the arm to the case.
Really, the only thing I would add to this system if I were the engineer would be a provision to monitor a spare tire (towing and towed vehicle/trailer), and perhaps a nicer quality case for the monitor. Of course, I suppose you can monitor a spare by using an un-used tire position - but the icon on the display won't be quite accurate.