TPMS - stem versus inside tire monitors

[Art-n-Marge]

I am in the market for a TPMS, but wanted to keep it as low cost as possible.

I had accepted that I would use stem mounted monitors on the TV and the RV tires and then would remove them when not towing since the TV would be 3,000 lbs lighter and I wouldn't want to risk damage or theft of the monitors.

However, now I'm thinking 100% monitoring would be better than part time monitoring so I might consider the internal tire monitor (at least for the truck) and justifying the higher cost.

I'd appreciate any member experiences on the external or internal monitors, pros and cons. For example, need or frequency of replacing the battery on an internal sensor?

[bncinwv]

Art,
We have the TST TPMS with the user replaceable batteries. We have the external stem mounted sensors and have learned a few things since installing them. The primary one is that the external sensors must have steel valve stems installed on the rig, truck or whatever you use them on. The slight weight is enough to deflect rubber stems and will cause leakage due to the centrifugal forces the sensors and stem are subjected to. The manufacturer states the life of the batteries vary between six months and a year, I just replaced the batteries on ours, they were low last fall and had no choice for this winter (this verifies the six month time-frame pretty close rather than the year). I did learn that if you remove the sensors from the vehicle, the battery drain is eliminated, so in other words I was wasting the batteries by leaving them on through winter months (although this will not apply to you since you have no winter months). With the TST models there is a special tool to install and remove them, so theft is not an issue, unless someone happens to have the tool (a special wrench). The internal sensors seem promising, and I am not sure of the life, but to replace batteries, you would have to break the tire down. We are happy with the external TST system. Just my thoughts!
Bingo

[Art-n-Marge]

Thanks, I should have mentioned, I was aware of the metal stems and do have them on both the TV and RV at the last tire change in anticipation of an eventual TPMS.

I thought I had read that the internal TPMS type batteries lasted a lot longer, but wanted to confirm. For the external model I guess the only way to stop battery drain is to remove the batteries from the sensor (another hassle I'd have to think about) when uninstalled. Thanks for bringing that up.

[grampachet]

We have the TST external sensors. Over three years and 7000 miles, batteries still OK. I have rubber stems, only one time have i had any problem and it was my fault, i didnt get the sensor on tight and it worked loose. My batteies are not replaceable so i remove sensors when stationary for anything over a month. The brochure says up to five years battery life then send them back for new batteries at a considerable cost. I am the guy who lost the monitor somehow and the company sent me a new monitor at no cost. I am still impressed with this company!

[WeBeFulltime]

I recently had trouble with my TST transmitters and was just a few days out of warranty. I called them anyway and I am proud to report that they took very good care of me. I will be happy to purchase from them again! Good product...better people!

[dieselguy]

I have the replaceable battery external sensors on my fiver and boat trailer only. The replaceable battery type like mentioned are supposed to last somewhere betweeen 6-12 months. There is an external sensor that requires the user to send them in when the battery gets low ... it's average battery life is a few years I think. The internal sensors as you know require a dismount and remount of your tires, but the batteries are supposed to last several years ... about the average tire life before you need to buy new ones. I'd venture just change the batteries when you change tires. Only catch is ... you're going to have to send the internal sensors in to get the batteries changed ... read truck with no tires for a few days unless you like spending dollars on unmount and mount fees. I like others remove my sensors during the winter months ... it only takes less than 10 minutes of your time to screw them back on and reprogram ... a non issue for me. The flow thru stems are better than what I have, but they are more noticable and look a bit too "Buck Rogers" to me perched off the valve stem.

[BusyCarol]

We have the TST TPMS and we LOVE it! We have the flow-through type where you can still air-up the tires even with the sensors on. We take them off when the trailer is going to sit and reset them up when it is time to head out. It is about a 15minute procedure. When we went to Quartzsite we realized that we had left the charger at home. We stopped by the TST booth to buy a new charger and the gal gave us one for free. She told us anytime we lost it to just call and they would take care of us!!! GREAT CUSTOMER SERVICE!!! I had one question when I was setting up the system and they walked me through the answer over the phone within a matter of minutes. I was super impressed!

It is kind of fun to watch, as a passenger, the tire pressure and temperature changes that occur while driving. It makes me feel safer knowing that something will alert us to an issue. Hope that helps! Good luck with your decision!

[Denfinger]

We have had the TST system for 4 years, at first on our Travel Trailer and now on our Montana. We love the peace of mind knowing that we are not going down the road with a tire going bad. A flat tire on our TT was alarmed immediately and we pulled off the road for repair with no damage. Well worth the time and money. YES, metal valve stems are HIGHLY recommended. The company is great and the replaceable batteries on teh sendors are the way to go. As stated remove them while in storage to save batteries. TST stands behind their products.

[woodtic]

I also have the TST flow through with replaceable batteries. I like them a lot. I marked each one with a paint marker so I can replace them on the same wheel every time ( no reprogramming required ). Very easyto instal and remove. Monitor is small and easy to put in your pocket which is great when topping off the tires and getting the pressure just right. Only problem I have had with them is occasionally one will loose contact with the received.

[Art-n-Marge]

Looks like the TST system is popular so far. I'm surprised there are no Pressure Pro, Hawkshead or other brands responding on their experiences, yet. I didn't realize replacing the batteries might require one to send them back to the factory but it makes sense for keeping things sealed correctly. This adds to maintenance time and costs for this step unless I can find a local vendor for convenience sake.

So far, I'll stick to the original stem mounted sensor plan. The internal ones are more work and requires synchronization with new tires - we don't travel as far so the tires might last way longer than the internal sensors.

For TST are the receiver and the user interface in the same unit? I have seen some systems where the receiving unit can be positioned towards the rear of the TV (to improve reception for the rear trailer tires) and then a wire is run to the user interace unit in the cab.

[bncinwv]

No wires, our single display is about credit card sized and can be window mounted with a suction type mount or ours came with a small stand that I sit on our center console area. Plugs into cigarette lighter (I guess they are called power outlets now?) and has a self-contained battery so it can be used without being plugged in as well. Display constantly rotates between the sensors showing temp and pressure for each tire before rolling to the next one. The sensors I have use the CR1632 coin-type lithium batteries which are relatively cheap as well. The system is expandable for up to 22 tires, I monitor the four on the rig and the four on the back of the truck (mainly for inside dually purpose). No problems with reception, I can actually read the trailer tires for about a quarter mile after I leave the mini-storage if I don't turn the unit off.
Bingo

[Bigsky3625RE]

We use the TST 507 with user replaceable batteries. Going on one year and the batteries are still good.

We do take them off when not traveling.

It is nice to be able to see the pressure and temp. as we travel.

If we are on a trip we leave them on. When we get ready to go, I turn the monitor on as we are getting ready. That way I can see the pressure and know if I need to take out the compressor and top off a tire.

I highly recommend the TST products.

[grampachet]

Art, bought mine before there were the replaceable batteries. Mine are sealed and require sending back to TST to replace batteries. They did state the batteries were good for UP TO five years. So far do good.

[seahunter]

Art,

It is confusing but there are replaceable batteries, but there are alos USER replaceable batteries with the TST. I had purchased the non-flow through sensors, but never mounted them because I am having trouble finding valve extenders. I called TST and they said since I had never mounted them I could exchange them for the flow-through sensors. Much easier as you don't have to remove the sensors to air up. The sensors might be a little larger, but if you have the 135 degree valve extenders, you can just rotate them so the sensors tuck in farther. I have all the valve extenders so far except for the inside duallies.

[Art-n-Marge]

Okay, now you all got me thinking (in a positive way) about the external sensors mostly because if I can change the batteries myself, then that's the most convenient.

To extend battery life I can see trying to remove the sensors, but does this mean the sensors stop transmitting when they are removed? Is there actually some pressure switch that turns the sensor off? Does the amount of pressure on the pin from the valve stem act as the on/off switch? Otherwise it doesn't seem that removing the sensor would stop the transmitting and therefore the battery drain.

[bncinwv]

My understanding is that if there is no pressure on the sensor, it does not transmit. I have eight sensors, and until I get the steel valve stems on the dually tires, the extra four are riding in the truck console within inches of the monitor in the truck. The monitor did not pick them up, so I deleted those four locations from the monitor. Simply put, it is like the Ford commercial, it is magic!!
Bingo

[dieselguy]

I'll back up what has been stated ... when the sensors are off your valve stems ... they do not transmit or use battery life. Think about it ... if they transmitted all the time, the moment they were manufactured, the clock would be ticking on battery life. In reality, this battery life thing isn't such a big deal. The batteries are relatively cheap and plentiful at least on my TST system. Unless you get the flow thru, you're going to have to remove them from time to time to top off the tires anyways. Programming is a breeze ... you'll spend more time taking a shower than you will setting them up. If you remove one and put it right back on the same tire ... there is no reprogramming.

[jswharton]

I've got the Hawkshead and they work great. Have the on the trailer only, external, and remove them when sitting over a couple weeks. Each sensor is numbered and if you get them back on the same wheel there is no reprogramming, takes 2 minutes. Batteries are easy to change and have extra gaskets. There is a a gasket on the cap where the battery is, split 1 on the 1st battery replacement. The other gasket is for the v e stem. Hard to replace and be sure to get it set otherwise it won't seal and loos air. Can handle 22 wheels I think. I check Ir pressure any time I remove the sensors and when they go back on, the reading are the sakes as the digital gauge. Saved my beacon once with a nail. Never have had an issue with the components but the original purchase was shipped quick as we're the gaskets, less than a week.

Overall grade = A

[rafisch]

For those of you that have the TST TPMS, do you also have the repeater antenna? Where & how did you mount it?

[bncinwv]

We have a dually and a 39 foot rig and do not have any need for the repeater. As mentioned earlier, I can still read the tire presure and temperature long after leaving the rig at the storage lot, if I forget to turn the monitor off.
Bingo