These are the causes that I've experienced with flat tires.

Damaged Tires. Usually nails or screws. Seem to be common around Home
Depot parking lots.

Bent rims. If your rim is sufficiently bend  you can lose the seal on
the edge that keeps it airtight. This is usually NOT a slow leak.

Valve stems. Old valves rubber can leak. New valves helps deal with
this. Alternatively the INSIDE of the valve (the removable part) might
not be fully tightened down. This is usually noticed by a bit of air
pressure released when you take the dust cap off. A common high school
prank was to loosen these giving people flat tires.

And now for something REALLY subtle (and not likely an issue for
Vanagon folk). If you have chromed wheels, it is possible the chrome
job is pealing off. This can allow for air to leak UNDER the chrome.
Darn near impossible to fix, except by stripping of the chrome.

On Dec 21, 2005, at 10:52 AM, peter cobb wrote:

> I too seem to get more flat tires on my vanagon than my car i  have a
> syncro and use 195  r 14 nokian c2 Hakkapeliitta i am always checking
> the tire pressure and seems like always going down.  i am wondering if
> there could be  any damages to the rims.  has any one else  had any
> experience  like this.?
>
> peter cobb
> 90 syincro westy