Installing Tire Pressure Monitors

[cruncher]

I purchased a set of TST tire pressure monitors in August. I programmed the sensors for my 2015 Sprinter-based Motorhome (Coachmen Prism, Class C), and I took the set to Les Schwab (local tire chain) for installation. I told them that I needed rigid metal valve stems installed to avoid vibration that could lead to leakage, which I had learned during research prior to purchasing the set of sensors. They took one front wheel off, verifying that no factor monitors were present, and found that their metal stems would not seat correctly with the curvature of the M-B wheel. Further, they advised that the sensors wouldn't work with the vanity chrome wheel covers, and the front sensors would run the risk of hitting a curb because they stuck out so far. So nothing was done on my installation, and they did not charge for the advice.
Have you heard of similar problems with Sprinter chassis wheels, and what was done to correct the problem? I feel the sensors are very necessary, as we experienced leakage from a valve stem extension on the outside dual twice on a 2,000 mile trip that we just completed this morning. I understand that polished aluminum rims are a potential solution for the front and the outside duels, but that the inside duel must remain a steel wheel to accommodate the M-B lug bolts. If I blow $1,400 for the aluminum rims, I’d still be stuck with the inside duels not being able to have monitors because of the curvature? With so many Sprinter 3500 vehicles being sold, this must be some mis-information being given to me, or are aftermarket pressure monitors not compatitable with this type of vehicle?
I would appreciate any advice from someone who has had similar problems. My next step is to go to another tire shop that is willing to tackle the situation, but I thought it best to ask the forum first to see if there is any insight.
Thanks in advance - Steve (posting same on the Sprinter Forum)

[btritschler1437]

Contact TST to see if they have any advice for you.

[JLeising]

I found a shop that had special small diameter metal stems with extended mounting nuts that fit the wheels (just). Problem is being able to get a wrench on the nut on the outside of the stem to tighten it down properly. Others have used metal "dually" stems that fit (search the forum) (e.g, http://www.forestriverforums.com/for...ems-45080.html) - but are wheel position specific (dual outers and inners can't be put on other wheel locations; can't rotate tires without demounting and switching valve stems around). Suspect internal pressure sensors might work and not require metal stems. It is a problem with the Sprinter wheels.

[cruncher]

Thanks for the responses. After consulting with the local Sprinter dealer and the local tire shop that they use, I have decided to install high-pressure rubber valve stems to replace the Coachmen installed long rubber stems. WheelMaster makes and guarantees extension hoses and mounting hardware for TPMS sensors, but they need a stiff valve stem for the base "foundation" of the hose. The tire dealer showed me exactly why the steel wheels for the 3500 do not work with metal stems, and quite possibly that is the reason that MB does not factory install monitors on the 3500's.

I'll report back on this noble experiment (or foolhardy venture) when I complete. I am amazed that MB does not even mention in the Owners Manual that the info on tire pressure sensors does not apply to the 3500. The dealer said that they understand that Sprinter will be coming out with super-single tires to replace the duels on the new 3500's, possibly so sensors will be compatible, but I'm a year too early for that fix.

[Prism 24G]

I did all by my self, at Sprinter Prism 24 G
Ordered brackets for rear dual and on
front wheels they have steel mounted
valve housing and have no vibration.

[conceptumator]

No experience with the Sprinter but I may have some input for you. I read several reviews where folks indicated there was a danger of striking a curb with smaller wheels if you used the flow through type sensors. For that reason, I used the flow through type on the Legacy and got the other smaller sensors for the toad. I don't have the metal stems on the toad but so far haven't had a problem. Will change them if it starts to be an issue. Might see if TST will swap the sensors for you since it's a new set.

[JLeising]

Long thread that covers this issue for the Sprinter 3500 in the Solera sub forum:
http://www.forestriverforums.com/for...t-15493-8.html
There are metal valve stems that fit (unless Mercedes changed rims since our 2012) - hard to find, but they exist. Link to a source in post 72 of the thread above, I believe.
Without the added weight of a TPMS I have had two of the "high pressure rubber" stems fail (gracefully- slow leaks I caught on morning pressure checks). Both were attributed to "improper installation - pulled too hard installing and torn". I lost confidence in the rubber stems.
FYI
Jim

[RailwayRog]

Contact this guy Tire-Man: Home Page
I have these valve stems on my sprinter 3500 but I'm not running tpms so i can't help beyond that. Though I might be interested in tpms if someone has success.

[jeffrapp]

I have a 2015 Prism 24G. I found a tire store (mcCleas, Santa Rosa, Ca and other locations) that installed new metal valve stems for me, on all the tires. They claimed the rubber ones were not suited to the demands.
They spent a long time custom bending the stems, so that all now are easily accessed outside the wheel covers for filling.
I installed the TPMS myself.
I think you do have to be careful about the stems sticking out, so you don't break them.
So far, very happy with the set up.

[Dennise]

I have a 2015 Prism 2150 LE, with Dicor SS Wheel liners. I installed a eZ-Tire TPMS system from Eez TV Products myself on all 6-tires + spare tire. This wasn't a straightforward project, but it was successful. Here's what I did.

First I wanted metal valve stems all around. Seeing a metal extension from both inside rear tires, I mistakenly thought these stems were ALL metal. So I ordered 4- metal valve stems from Your Tire Shop Supply - 2-front stems and 2- outside rear stems. The folks there were knowledgeable and helpful. They have metal stems for MB Sprinters. Then I had a local tire shop install the 4-metal stems. There did appear to be a problem with the Sprinter's wheel curvature accepting the metal stems, but I thought there was enough margin so I accepted the installation. It was then I noticed the rear INSIDE valve stems were NOT all metal - only the extenders added to allow access via the outside rear wheel were metal. These extenders were passed through 'rubber doughnut' stabilizers mounted on the outside rear wheels. The stabilizers in my judgement were robust enough to keep the connected rubber stems (attached directly to the inner rears) from flopping around. So .... I ended up with all metal stems on the two fronts and the two outside wheels, but NOT the inner rears or the spare. Now for the 2nd problem.

The new front metal stems did not extend far enough through the decorative Dicor front wheel liners to allow attachment of the ez-tire TMPS sensors, but the sensors attached easily to the the 4-rear and the spare tire valves. So .... I was forced to enlarge one of the wheel liner holes on each front liner to allow attachment and chuck access to the TMPS sensors.

Once you gain clear access to the valve stems, attaching and programming the ez-tire sensors is simple if you follow the instruction very carefully.

So far so good, I can easily read temps and pressures for all 7-tires, but the real test will come during a long road trip planned for November.

The installation was a real hassle, but I hope it pays off.

Good luck to you.

[cruncher]

Thanks for the "whole enchalata" on your experience. I'm doing the stainless extention hose route, bolted to the center hub of the chrome wheel cover on the rears, trying to reduce the load of the TST sensors on the stems. The front will be similar to your modified cover solution. Please keep me posted on any further problems, and I'll do the same. Only one trip before the sensors are installed on the 5th of October. ...crossing my fingers!

[Hugh R]

I know several people that found that the screw on flexible tire extender hoses leaked, or broke loose and flopped around. Consider the hard extensions, you will have to remove, and re-balance the rear inner tires, but long term you'll forget about the added expense.

[skiprennell]

Originally Posted by cruncher

I purchased a set of TST tire pressure monitors in August. I programmed the sensors for my 2015 Sprinter-based Motorhome (Coachmen Prism, Class C), and I took the set to Les Schwab (local tire chain) for installation. I told them that I needed rigid metal valve stems installed to avoid vibration that could lead to leakage, which I had learned during research prior to purchasing the set of sensors. They took one front wheel off, verifying that no factor monitors were present, and found that their metal stems would not seat correctly with the curvature of the M-B wheel. Further, they advised that the sensors wouldn't work with the vanity chrome wheel covers, and the front sensors would run the risk of hitting a curb because they stuck out so far. So nothing was done on my installation, and they did not charge for the advice.
Have you heard of similar problems with Sprinter chassis wheels, and what was done to correct the problem? I feel the sensors are very necessary, as we experienced leakage from a valve stem extension on the outside dual twice on a 2,000 mile trip that we just completed this morning. I understand that polished aluminum rims are a potential solution for the front and the outside duels, but that the inside duel must remain a steel wheel to accommodate the M-B lug bolts. If I blow $1,400 for the aluminum rims, I’d still be stuck with the inside duels not being able to have monitors because of the curvature? With so many Sprinter 3500 vehicles being sold, this must be some mis-information being given to me, or are aftermarket pressure monitors not compatiable with this type of vehicle?
I would appreciate any advice from someone who has had similar problems. My next step is to go to another tire shop that is willing to tackle the situation, but I thought it best to ask the forum first to see if there is any insight.
Thanks in advance - Steve (posting same on the Sprinter Forum)

Hi Steve and the rest of this forum. I struggled with how to properly inflate and monitor tire pressure with our MB Sprinter RV. The issue is most certainly the fact that the MB standard wheel requires a special valve stem. The easy way to resolve the problem is to use rubber valve stems which is exactly what MB does. Rubber valve stems are only rated at 65 psi, but the standard tire is rated up to 80 psi. Factory specs call for 61 psi so the rubber valve stem is appropriate and fits the curve of the MB steel wheel. Here comes the problem. Most of us aren't tire mechanics. Also in order to cure the problem of checking and filling the Sprinter tires you are faced with reversed wheels and the inability to check tire pressure without proper truck tire knowledge and equipment. After nearly 9 months I have solved the problem. I worked with our local MB car dealer (not much help) and a local truck tire repair facility (also not much help). However, what I learned from my lengthy efforts is that you can purchase a Sprinter specific valve stem package from Camping World where they sell solid metal valve stems manufactured by Wheel Masters. The Wheel Masters solid metal valve stems cure the issue for the dual rear wheels, but not for the front tires. Please note that all is OK if you leave the beauty rings off your wheels. I wanted my RV to look its best with the beauty rings so I still needed to find a solution for the front wheels when using the beauty rings. The only option I was able to find was the snap in rubber and metal valve stem rated up to 80 psi. The rubber high pressure rubber snap in valve stem worked just find and then I mated it with a 2 inch straight valve extender from Wheel Master, also purchased at Camping World. I used Permatex medium strength bonding agent on the high pressure valve threads when attaching the solid metal 2 inch wheel master valve extenders. All six wheel beauty rings are now installed together with a TPMS tire pressure monitoring system. The plus to my efforts is that the dual wheels don't have valve extenders. My dual wheels have solid metal valve stems. The front tires have high pressure valve stems which is a serious upgrade over the original MB rubber valve stem. Wheel Masters saved the day together with the high pressure valve stems. I hope my post helps fellow MB Sprinter RV owners.

[Blackhat6mike]

A little off subject, but called TST Friday to get a few of the "metric" O rings that are inside each external sensor. The lady said she would send me several of the O rings AND the seals [larger O rings] that should be changed each time the battery is changed for FREE. Yep, FREE!
They said all owners of the TST systems should do preventive maintenance and for everybody to call and they would supply the O rings for free. Now that is service! Just thought I would pass this on. 1-770-889-9102

[Hugh R]

Tire minder does the same thing. They will also replace the batteries for the first two years for free.