TPMS and Rubber Tire Stems

[RMNummi]

Another quick note for the thread on rookie mistakes with a 23d. Had 2 back to back incidents a month apart where different tires developed leaks while underway..when having the tires checked at tire shop guy says “Your tires are fine, but you have rubber stems… I see you have added TPMS to your tires. We see this a lot, you need to have metal stems when you add sensors. The weight of the TPMS sensors has caused the rubber stems to develop stress cracks, that’s where your problem is”. He reaches down and bends the rubber stem, sure enough, tell-tale hiss of escaping air. I had all the rubber stems replaced w/ metal and haven’t had a problem since.

Needless to say I was thanking the RV Gods that I bought a 23D, the smallest “twin axle” AS. Couldn’t imagine consequences of making this rookie mistake w a single axle. When those rubber stems, TPMS worked as advertised, squawking while tire pressure went from full to 10psi in about 10 minutes. Truly the deity takes care of idiots and fools w their first trailer.

[richard5933]

This problem is not limited to dealing with the TPMS sensors. When I bought my new Goodyear Endurance tires they were mounted on the rims using an all-rubber valve stem. Since these tires have an upper inflation limit of 80psi, they required suitable metal stems.

I didn't catch this right away or I would have had them install the correct valve stems and not have to go back for a remount. Obviously this is something others will encounter when they replace older (lower pressure) tires with the new GY Endurance of other similar tires.

[gypsydad]

I have used my TST TPMS system for 4 years now, (48K miles on our 28'). I have used rubber valve steams and no issues. (knock on wood). I am on my 2nd set of GYE's. I understand the concerns on the rubber valve stems, and will likely change at some point to metal. I do use our AS a lot; and I do inspect the tires before and during each trip including valve stems. I also make sure the tires are at 58-60PSI when cold. Interesting you had issues with the valve steams cracking/leaking. Have not had that issue with mine....yet.

[RMNummi]

All my stories start out with “There I was…”. Yep, first time it happened was in, I kid you not… Yeehaw Junction. Second was on I95 North of Jacksonville… after the second time I scratched my head and tried to figure out what I had done to screw things up. Only tire related change was addition of TPMS. I guess their are different micro-gram weights of the diff weren’t brands of TPMS sensors but sheesh. A techno-geek friend was observing that the wind resistance and circular rotation speed of same combined with age of stem/rubber etc. could all be contributing factors…. Me, I just said “never again” and did a little preventative maintenance. Facetiously speaking, I’ll say that I’ve never seen any posts on any forum like “How your TPMS Sensor could kill you”.

[Jeff7176]

I have been to Yeehaw Junction. But back in topic,

our original wheels and tires were 15 inch Sendels with GYE tires. We added Tire Minder TPMS (which are OK, but I think I would rather try another brand) within a few months of delivery. After a few years I noticed the rubber stems we're all cracked. Fortunately not enough to leak, but I was definitely surprised. When we got new tire we opted for.metal stems. All is well since.

[WhereStream]

One question about metal stems (I currently have rubber stems but can change that when I get new tires, probably next year).

Is there a problem with metal (steel, I assume) stems mounted to aluminum wheels?

[richard5933]

Originally Posted by WhereStream

One question about metal stems (I currently have rubber stems but can change that when I get new tires, probably next year).

Is there a problem with metal (steel, I assume) stems mounted to aluminum wheels?

There is still rubber in contact with the wheel - that serves both as a metal-to-metal isolator and as an air seal.

Here is a good side-by-side look at what's out there: https://www.discounttire.com/learn/valve-stems

It's not necessary to get the all-metal valve stems like you see on tractor trailers and heavy trucks. The ones labeled "high press" with the rubber base are what I'm running. I call them metal vs. rubber since they have a stretch of metal exposed and are not rubber all the way up the stem. They are much stiffer and stout than the all rubber version.

[Salvagediver]

Troops,

I used the subject steel valve stem for use with the TST TPMS. It fits the .453" valve access on the alloys and the locking nut clears the recess so a socket will fit. I think they were about $2 a pop. Don't forget the spare!

[CRH]

I put new HP brass/rubber valve stems in with my first set of replacement tires on the AS. I had one that leaked. It left me with a flat the day I was leaving a campground. I pumped the tire up and it held pressure for days. I discovered the valve stem leaked if I pushed it sideways. I bought some bolt in stems from the auto parts store and put them.

[gypsydad]

OK; I understand the comments from earlier posts on the rubber valve stems not holding up to the TPMS screw on monitors vs the steal valve stems. Was wondering why I am not having issues like many have posted. I went to my AS yesterday and looked; mine are rubber on top of steal base. They are very stiff, infact, I can not easily move the screw on monitor caps. I then went to my friends new Winnebago 26' and he has 15" off road tires; he just received his TPMS system and wanted my help to install; his valve stems were rubber, but I could easily push them from side to side; no metal at the base of the rubber. I didn't realize they make 2 types of rubber valve stems?? Could explain why some folks have issues and others (including me) have not?

[Mollysdad]

Originally Posted by RMNummi

Couldn’t imagine consequences of making this rookie mistake w a single axle. When those rubber stems, TPMS worked as advertised, squawking while tire pressure went from full to 10psi in about 10 minutes. Truly the deity takes care of idiots and fools w their first trailer.

Been there, done that. Here's how it goes. Rewind about 20 years and I'm towing an enclosed motorcycle trailer with two bikes. Back then trailer tires were all alike, black, round, and more or less held air. Cheaper was better.
My tow vehicle is a 40' MH. All is well.....until it's not.
Westbound on I-70 in Kansas a UPS semi pulls up alongside and waves me to the trailer. I know the message. First, I look at the backup camera and all looks fine.
I pull over to the breakdown lane and discover one fender is gone, there's a lot of black streaks both on the trailer and the back of the MH, and the tire is reduced to two wire beads with some scraps of rubber. The rim is unsalvageable.
I'm prepared with a spare, boards, a bottle jack, so the tire is changed and I'm on my way. But my vacation is now compromised because I'm shopping for a rim and tire using a motorcycle, and I'm not exactly in a big city. I find one for $120, rim, round black no name tire. The trailer is butt ugly with no fender, and when I get home I have to locate a trailer fender (specific/fiberglass) $110.
During the time I drove on the rim, I never heard anything or felt anything or saw anything. Of course the MH was heavy compared to a single axle trailer with two bikes.
I'll never tow a single axle trailer long distances and I'll know what tires and their ratings.
It turns out the trailer was made using the wrong "drop" on the axle and the builder just welded a block under the mount to raise it up. (He used an axle meant for a garageable trailer and mine was not. So the fender was closer to the tread than needed) Did that contribute? We'll never know.

On the positive side, I had a stranger stop and offer to help. That made my day. Back east I'd worry that someone stopping meant he was about to say, "This just isn't going to be your day, now is it? My name is Bob, I'll be your robber."

Originally Posted by WhereStream

Is there a problem with metal (steel, I assume) stems mounted to aluminum wheels?

If you use the Dill 902-W, the stem is brass with metal coating. But regardless, the stem sits in a rubber washer so it never touches the rim.

[StevenD]

Interesting comments. We recently purchased new GY Endurance and 15 inch Sendel wheels from America’s Tire here locally. Based upon the sage advice of the forums, I had asked for all metal valve stems but they told me they no longer offered them due to sealing issues. If I insisted on all metal, I would have to supply them and it was questionable if they woul warrant the installation. I ended up with the high pressure brass/rubber versions.

[bbcubed53]

Here is a thread I started in 2020. I'm convinced if you're going to add TPMS you need metal valve stems.

https://www.airforums.com/forums/f43...ms-209319.html

[drbrick]

Yap - when we install GYE a year ago - metal stems as we run the "flow thru sensor" TST which are heavier then the standard sensor.

[OrangeCrush]

Dang, I just checked and mine are rubber. Thanks for the heads up. I use the EezRV TPMS which looks just like the TST. Sensors are pretty small. They work OK but I have not been super thrilled with them as the seals started leaking after 2 years and range is barely adequate. So thinking about it, if rubber stems are not adequate and you have to replace them anyway, why not go to an internal design sensor like in most vehicles? Anyone have an internal sensor kit they can recommend, something like this maybe?
http://www.trailertpms.com

[banderabob]

We had a 23 D for five years, rubber stems, TireMinder TPMS. No leak issues. Our current 25FCFBT has metal, no issues. Maybe the stems on your 23D had “dry rotted”. The addition of a pressure sensor on any stem should not impact the integrity of that stem. Just think about it.

[Spaggs]

Dill VS-902W
Dill valve stems are made in USA. I bought mine from Discount Tire for about $3 a piece. I’ve got the TST flow through sensors so there is bit more weight and length added.
If you’re going to spend a bunch of money on a TPMS, purchase a little insurance with the metal stems. One less thing to worry about.
Just my 2 cents.

[RMNummi]

Well…. That’s true, it could have been dry rot. I can’t rule it out as I purchased the 2014 AS in 2019 and have no idea how the PO treated the tires ie UV exposure etc. Like Sargent Friday, I just report the facts. Original tires on original rims… variation: Addition of TST TPMS. I went back and viewed the “manual” after the tire tech made his observation and sho nuff, in fine print, “recommended for installation on metallic stems only”…….the individual monitors weigh next to nothing. After said event, I purchased four new GYE tires, metal stems and no further issues. Thanking the deity I was/had:
A. Two axles.
B. Near an off-ramp during normal business hours w an open tire store.
C. Relatively used tires enabling no guilt replacement.
D. A good spare for the first incident (in the middle of alligator alley).
E. My trusty DeWalt battery powered inflator.
F. Learned a lesson about reading the fine print in new equipment.

So yeah, it was an empirical observation, it coulda been stem rubber rot, but hey, why not pass on my story to the AS forum crew. Maybe some other newb is/was getting their tires changed and learns to say “metal stems please”.

[MichaelS]

I bought TPMS flow thru sensors when I installed new tires before a long trip a couple months ago. I supplied metal stems but the shop didn't use them, installed rubber. I didn't notice until installing the sensors the day before departure. The stem stuck through the hubcap snugly, so I made the decision to go with it as they would be supported by the hubcap.



Worked fine until the hubcap came off, pulling the valve stem out with it

[SuperTrouper]

I dutifully put steel stems on the trailer, forgetting about the TV. Heading toward Idaho Falls at 60MPH a few years ago (heading to Yellowstone) with a 40MPH quartering side wind in front of a closing thunderstorm I lost my RF pressure on the Excursion due to a split rubber stem. TPMS and Quick Lane tire in Idaho Falls saved our butts that day. Steel stems all around ever since. - Brad