Slow leak

[ladderman]

Hi,
        I had new Avons put  on my Valk about a month ago.  I was checking air pressure and noticed the rear tires hard plastic enclosure around the valve stem was broken, I removed it.  the rear tire seems to lose about 5lbs in a weeks time.  Does this plastic piece have anything to do with maintaining air pressure?  I'm going back to the stealer and have them check the valve stem, thanks.
                                                       Ladderman

[Steve K (IA)]

That little black plastic piece keeps the valve stem from flexing...I think mainly when adding air.  Keeps you from pushing the stem back and weakening the rubber seal.  I have had to replace only one of those between both Valks.  It just came up missing.  About the leak...I think it is the tires.  When I had Avon tires on my I/S, I was always adding air, every week just like you.   Since putting Dunlop E3's on, I only have to add 2 or 3 times a year.  I have Metzlers on my Std and they don't loose much air either.

[R J]

Hi,
       I had new Avons put  on my Valk about a month ago.  I was checking air pressure and noticed the rear tires hard plastic enclosure around the valve stem was broken, I removed it.  the rear tire seems to lose about 5lbs in a weeks time.  Does this plastic piece have anything to do with maintaining air pressure?  I'm going back to the stealer and have them check the valve stem, thanks.
                                                      Ladderman

You are losing air from the stem flexing.  That piece of plastic is to hold the stem solid, so to speak.

Your best bet is to replace the stem with a 90* metal one.  
Here is the link.

http://patchboy.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=P&Product_Code=17-562&Category_Code=6-3

[Scott from FL, now in Maine]

If you leave the OEM stems on the bike, you NEED that plastic support peice. My front one was missing and I ignored it. It took awhile, not sure how long, but the flexing of centrifical force wore our the stem. It blew off at 45 mph in a corner!! 40 psi to ZERO in under a tenth of a second! Fortunately I was able to straighten it up and ride it off rode in to a parking lot! After that I took no chances and replaced the stems with these.   

http://patchboy.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=P&Product_Code=17-562&Category_Code=VS-1

[R J]

Scott in FL, we think along the same line there.........

[Thunderbolt]

They work great.  If you don't use those, you need to replace that plastic piece.  It's function is to keep the stem from flexing at high speed and losing air.  The ones from Patchboy are metal and you don't need the plastic retainer.

[ladderman]

They work great.  If you don't use those, you need to replace that plastic piece.  It's function is to keep the stem from flexing at high speed and losing air.  The ones from Patchboy are metal and you don't need the plastic retainer.

Thanks for the info guys --   Ladderman

[RoboCop]

You are losing air from the stem flexing.  That piece of plastic is to hold the stem solid, so to speak.

Your best bet is to replace the stem with a 90* metal one.  
Here is the link.

http://patchboy.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=P&Product_Code=17-562&Category_Code=6-3

thanks for that link, I keep seeing these high dollar valve stems show up on other forums but I'm too cheap.

http://kurveygirl.com/shop/product_info.php?cPath=27&products_id=145

[MP]

+1 on the patchboy ones.  Best out there.  Shipping is the only killer from them.  See if you can go in with some others on getting a bunch at a time.
MP

[Ricky-D]

40 psi to ZERO in under a tenth of a second!

I think that is a bit of an overstatement.

Drama, drama.  Just the facts ma'am.