95 A6 5-bolt wheels

[Mark R]

Rims themselves can leak air due to porosity.  In fact, GM has a TSB out
covering a lot of vehicles for this.  Obviously, this would be a very slow
leak.  Tires also have some porosity, so you WILL loose some presure over
time, but it's quite small (like 1-2 PSI per month).  If you can measure a
PSI drop in a day or two, there's another issue going on than normal loss.
More common leaks are at the bead (bent rim, crack, cut bead when mounting
tire, corrosion) and valve stem.  Unless you have bolted valves (which I use
whenever possible), the common valve stem leaks are at the seal (they're
just snapped in, so any corrosion or out-of-round or high speed deformation
can cause leaks).  Too long of a valve stem can deflect at high speed and
cause leaking.  Of course, the easiest leak to fix is a valve core.  Only
use high temp (red seal) valve cores.  Easy to change out, and the normal
(black rubber seal) valve cores often leak.

In other words, find the leak if you can.  Valve core leaks can be repaired
yourself.

Mark Rosenkrantz


On 8/15/07, Grant Lenahan <glenahan at vfemail.net> wrote:
>
> leaky valve, of course!
>
> Grant
>