water pump mounting plate pitted

[Joshua Van Tol]

>
> You're talking to "The Anti-Silicone" here.  Rubber o-ring sealing
> mechanisms are designed to have the rubber mate directly to the metal
> surfaces.  You're adding a layer of an unplanned-for substance, thereby
> increasing the chances for a leak.  36 years of professional wrenching has
> taught me to avoid that stuff like the plague, except for where the correct
> variety for the job is called for.  John
>

True enough, they're also designed for flat metal surfaces. My anecdotal
experience (sample size of 20 or so) is that when the chips are down, and
you have no other choice, the solid loaded varieties of silicone sealant
(such as permatex gray) seem to work fine at patching up irregular surfaces.

Keep in mind too that the usage of a rubber o-ring on the water pump was
really a pretty poor choice on Audi's part, likewise the usage of rubber
gaskets on the vanagon engine was a pretty poor choice as well.