W211 420CDI 2008 Tyre pressure monitoring system
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Junior Member
Joined: Apr 2004
Posts: 64
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From: Europe
E420CDI 2008, GLK220CDI 2009
W211 420CDI 2008 Tyre pressure monitoring system
Hello every body can someone help?
One wheel is slightly leaking ( 0.2 bar per week) while the other do not leak at all.
The car is equipped with the Tyre Pressure Monitoring System. The default occurred after a valve cap has been removed for pressure check. Before it was not leaking at all.
I would like to avoid to removed the tyre.
Can some one post pictures of the TPMS and especially the inner part of the valve where it is in contact with the rim? is there any Gasket? or is it metal to metal contact?
I am thinking of re-tightning the valve from external. Is this a good solution?
Any other idea without removing the tyre would be highly appreciated?
Thanks in advance
One wheel is slightly leaking ( 0.2 bar per week) while the other do not leak at all.
The car is equipped with the Tyre Pressure Monitoring System. The default occurred after a valve cap has been removed for pressure check. Before it was not leaking at all.
I would like to avoid to removed the tyre.
Can some one post pictures of the TPMS and especially the inner part of the valve where it is in contact with the rim? is there any Gasket? or is it metal to metal contact?
I am thinking of re-tightning the valve from external. Is this a good solution?
Any other idea without removing the tyre would be highly appreciated?
Thanks in advance
Last edited by cc260E; Jun 28, 2012 at 11:14 AM.
Senior Member
Joined: Feb 2010
Posts: 431
Likes: 4
From: Cross Roads, PA
2008 ML320CDI
If you search google for Mercedes TPMS and select images, there should be some to come up that will show you what it looks like. Its possible but unlikely that removing the cap would have caused the leak.
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Joined: Jan 2007
Posts: 75
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From: NW Chiburb
04 E500
You can find training material on the TPMS at http://www.mercedestechstore.com/pdf...2006-20-02.pdf, but it may not be that complicated.
Spit on a finger (or dip it in a soapy water solution) and cover the valve stem with the finger. Look for bubbles. Bubbles indicate the Schrader valve is leaking. Debris may have gotten into it preventing it from closing completely, or (less likely) it might have somehow gotten loose or just failed.
If you see bubbles, depress the Schrader valve briefly and try to blow out the debris. Test again. This may take several tries. If this doesn't work, get a Schrader valve tool (may as well get a new Schrader valve at the same time) and try tightening the valve. If tightening the valve does not stop the leak, install the new valve.
If the initial test shows that the valve is not leaking, you can use the soapy water solution to check for leaks at the base of the valve stem, but it doesn't seem likely that just checking the pressure could cause a leak at that point. More likely it would just be a coincidence that it showed up after checking the pressure and you'd find the leak was actually somewhere else.
Spit on a finger (or dip it in a soapy water solution) and cover the valve stem with the finger. Look for bubbles. Bubbles indicate the Schrader valve is leaking. Debris may have gotten into it preventing it from closing completely, or (less likely) it might have somehow gotten loose or just failed.
If you see bubbles, depress the Schrader valve briefly and try to blow out the debris. Test again. This may take several tries. If this doesn't work, get a Schrader valve tool (may as well get a new Schrader valve at the same time) and try tightening the valve. If tightening the valve does not stop the leak, install the new valve.
If the initial test shows that the valve is not leaking, you can use the soapy water solution to check for leaks at the base of the valve stem, but it doesn't seem likely that just checking the pressure could cause a leak at that point. More likely it would just be a coincidence that it showed up after checking the pressure and you'd find the leak was actually somewhere else.
