So can someone explain to me what is up with these hi-tech valve stems and caps? My MA said I cannot use Rodney's (R53) UJ valve stem caps on Syd (R56), even tho they seem to fit fine. Is this some new kind of pressure monitor system? Does it work??

Man when BMW said they were redesigning R56 from the ground up (minus the body pan) a few years ago they werent kidding! My old stubby antenna doesnt even fit!

 

I believe that the stems are part of the Tire Presure Monitoring System (TPMS). There is also an internal TPMS sensor inside the tire as well.

I've noticed that new BMW's have the same type of funky looking valves we have on our Mini's.

 

New ones were redesigned to work with TPMS, I have the checkers on my MCS

 

MINI switched from the rotation monitoring TPS (done via ABS sensors on each wheel) to a RF sensor mounted inside the alloy...looks something like this>>


Way to spot is the old system has 'rubber' valve stems and the new stem is metal (as you can see in the pic). Probably dealer is saying that the valve cap is part and parcel with the new metal valve stem and thus not change. I think they are just playing it cautious since I have used aftermarket logo valve caps on a similar TPS (Corvette C6) system
Michael

 

Use them if you like but keep grease or oil on the threads! If you put them on without anything to stop corrosion, you will be ripping them off with pliers or vice grips! yes this happened to me on another car with TPMS and I destroyed the caps getting them off. The caps were locked tight onto the threads and it only took 4 months!

 

yes use them but grease the thread well

 

so... when I swap out my RSC all-seasons next spring and put my non-RF G-sports, will Discount Tire know how to deal with these fancy-pants stems?

seems like a lot of technological hassle for something a $2.99 tire gauge and some squat time can accomplish.

 

What kind of grease should I think of using? Would Anti-Seize compound work?

 

The problem is metal valve caps, which can result in corrosion from metal-to-metal contact. Using plastic caps avoids the problem. See this thread: https://www.northamericanmotoring.co...d.php?t=140987

 

dont see why not, if U like having that silvery goo all over yr fingers!

 

I believe the reason for the large caps is to make them easier for folks to remove & hopefully put air in their tires if needed. Old folks have trouble gripping small things. Most of the metal caps if not all that I have seen are made of stainless, so they aren't going to corrode & get stuck on the stem. If anyone leaves the caps on long enough for corrosion to become a problem shame on ya. Check your air pressure once a month at least.

 

How accurate is TPMS?

I like manually checking tire pressures on a regular basis with a good analog gauge (not the silly pencil kind). That also solves the issue of caps seizing onto the threads, since they're removed on a frequent basis.

 

Here is a quick snap shot of the TPS program>>

http://www.tirerack.com/tires/tirete....jsp?techid=44

And the more boring but important read from US DOT

http://www.tireindustry.org/pdf/TPMS_FinalRule_v3.pdf

Michael

 

Then my suggestion is still a good one. Check your pressures regularly. TPMS warns of 25% or greater under-inflation, but for performance and longevity sake I'd like to know when I'm just a couple lbs. off, and I won't have stuck valve stem caps.

 

Not while your driving though.

Still I have an RF TPMS on my Audi allroad, and have changed the valve caps a bunch of times, without problem, so I don't see why you couldn't. Unless this system is completely different.

 

You and I are in the same boat, and the answer is that we take our non-runflat tires mounted on the non-tpms rims and spend the coin to have Discount Tire install TPMS sensors OR just use them on the new MINI and see the flat tire warning light constantly on.
How's that for a run on sentence?

 

I 100% agree but remember TPS is for "the non informed I just want something to go to A-B and when something fails blame it on someone else and have them fix it and I do not have time to worry about things like oil changes, tire pressure or anything else beyond what I think is important" crowd... thus the idiot TPS system just like idiot lights. Sounds harsh but I been involved in the automotive side of life for more than 4 decades..just amazing how totally uninformed the 'average' driver is about their car... hell I would say about 90% don't even know where the car manual is.... Look at what car manufacturers emphasize.. cup holders, DVD players, stereos, gizmos etc and do you see or have you EVER seen ONE advertisement about RTFM

And yes not all TPS are created equal.. I have a 1990 ZR-1 Corvette which has a TPS on it (VERY high tech at the time) and it simply shows up on the car system info screen 'INF' meaning a low inflation issue on ONE of the tires not specifically on any tire... I also have a C6 Corvette and the TPS on it reads out on the Digital Information Center (DIC), actual tire pressure for each tire and I have checked the tire pressure using a professional analog dial tire gauge and the TPS info on the DIC is within 5% or less (most cases right on) of the gauge. As an aside, it is rather interesting to watch the DIC with tire pressure mode on and as you drive from cold tires to heated tires how much the tire pressures go up.
Michael

 

For just swapping out tires on the OEM rims, I don't think they need to do anything with the stems at all. However if you are also getting aftermarket rims, you'll have to buy TPMS stems or transfer them from the OEM rims.

 

Actually they need to be VERY careful on tire change out....an experienced tire changer will know where to break the bead on the tire and to make sure it is NOT where the sensor is located since you will damage or completely tear off the sensor. So for anyone going to a discount tire type company for tire changing ask one basic question... does the tech doing the tire changing know about how to change a tire a direct link TPS set up.
Michael