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Discussion Starter #1
I have heard of cuple of times where there has been a Valve Stem Failure due to the use of Metal or Heavy Plastic Valve Stem Caps.

Don't Do It!

The centrifugal force generated by the Cap can not only Cause Tick Marks on the Rim of the wheel but more importantly, can cause Tire Failure.


I have installed "Shorty" valve stems with regular lightweight plastic caps to avoid being stranded.
 

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There are valvestem supports out there to help with this.
When buying rims look for the stem moved inward and flatter.

Good tip Ocean's
 

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This is only using the heavy caps with the logos on them. The weight repeatedly bends the longer rubber stems and eventually causes them to crack. This could lead to catastrophic failure.

The lightweight stock metal caps are better than plastic ones because they serve as a backstop to the valve to keep it from leaking. They are light enough that they don't have the same tendency to bend the stems. When you get new tires and stems, get the short ones. The long ones really aren't necessary on the stock M5 wheels. (And go for rubber stems not the metal stems. I'm told by my tire guy that the metal ones tend to leak over time because they depend on a small O ring to seal the valve to the wheel. The O ring tends to shrivel over time and leak. The rubber ones should last at least as long as the tires. Always get new valves when getting new tires.)
 

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Does anyone know a source for the lightweight (aluminum?) valve stem caps that came on my 2003 as OEM? When I had new tires installed, they replaced the caps with the plastic ones, and really like the metal ones for the reason stated above (better seal).

:flag:
 

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Does anyone know a source for the lightweight (aluminum?) valve stem caps that came on my 2003 as OEM?
Doesn't the dealer carry them?
 

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FWIW, Sasco Sports, a reseller of real race tires, use a metal valve stem cap with a rubber seal. They also advocate using metal valve stem.
 

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Oh NO!!

Just purchased the M stems caps. Why?? Ok they looked cool. The dealership really should post a warning about this. $15 down the drain.

One thing that is interesting is that I bought the car used. Its a 2003 with 25K miles. I was having the wheels finished (there were some scuffs and small chips) and noticed the marks on the other side of the stem. This was before I replaced the rubber stock stems with the M caps. Any ideas to remedy this problem. I'll replace the M caps
ANDY
 

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Maybe is not caps, i have reg stems on front with lightweight metal caps and the marks are there, anything other than the stubbies is probably the culprit
 

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Let's not forget half of the wheel damage around the stems is caused by sloppy people at the dealerships checking tyre-pressure and scratching the wheel with their tools... I've got the short rubber stems with thin alloy caps. No problems, but I change tyres and stems at least twice a year. Trackdays.........



dark knight said:
Maybe is not caps, i have reg stems on front with lightweight metal caps and the marks are there, anything other than the stubbies is probably the culprit
 

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Stevie said:
Let's not forget half of the wheel damage around the stems is caused by sloppy people at the dealerships checking tyre-pressure and scratching the wheel with their tools... I've got the short rubber stems with thin alloy caps. No problems, but I change tyres and stems at least twice a year. Trackdays.........
Lets don't get complacent about this. Those rubber valve stems on a car traveling at high speed with heavy chrome plated brass decorative caps clearly deflects the valve stem 25% or more to not only touch the wheel but the damage it from the vibration. This over time weakens and ultimately cracks the stem, in my case cracking it in half. These marks in my posting photos clearly show the damage from the caps and not from some random tire tool or air hose. The scoring of the caps for grip helps this damage even more and finally, high performance cars almost exclusively use metal valve stems to avoid this centrifugal force deflection that is almost certainly to occur. Check Ferrari, Lambo, Porsche and all track cars to see this. Some may use very short and stiff stems.
:M5launch: :M5launch:
 

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Discussion Starter #14 (Edited)
Since Tire Balancers usually balance before they put on the Air Caps, I wonder if the weight of these could throw balance off a bit ?????

 

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And go for rubber stems not the metal stems. I'm told by my tire guy that the metal ones tend to leak over time because they depend on a small O ring to seal the valve to the wheel. The O ring tends to shrivel over time and leak. The rubber ones should last at least as long as the tires. Always get new valves when getting new tires.)
Whoa, I've been driving around with no valve * on 1 tire for a couple hundred miles, is that bad?

Edit*: valve cap
 

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Sorry to tell you guys, but the long rubber stems with the light weight metal caps also mark the rims at speed. And, the long stems are the only ones my dealer had (the largest or second largest dealer in the US).

I had new rims, new tires and new valve stems ... I removed the chrome sleeves over the stems and the heavier caps and replaced the caps with original caps ... still got scratches. And, now, after less than 2 years, the valve stems are showing signs of cracking ... and, yes, they were made in America.
 

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hey those maetal stems with rubber bases are primarily used for light/mid size trucks. you can get them at most places... they cost a bit more than standard stems, but they seem more sturdy than the rubber stems. they are made to hold up to 85PSI i think.
 

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Sorry to tell you guys, but the long rubber stems with the light weight metal caps also mark the rims at speed. And, the long stems are the only ones my dealer had (the largest or second largest dealer in the US).

I had new rims, new tires and new valve stems ... I removed the chrome sleeves over the stems and the heavier caps and replaced the caps with original caps ... still got scratches. And, now, after less than 2 years, the valve stems are showing signs of cracking ... and, yes, they were made in America.
RE: Just to clear the air, the stems on my car that deflected were the short rubber OEM stems from the BMW factory. So, short or long the result is the same with heavy metal decorative caps.
 
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