air bubbles

[John Hofstetter <hofs@domain.elided>]

>My concern is this is a subtle hint of a pump getting ready to fail.   =
>
>
>Doug =

Doug,
I don't see how the air bubbles in your gas could be indicative of 
imminent pump failure. It seems to me that if air can get by the 
diaphragm, gas can too, and you'd either be getting gas in the crankcase 
or see it externally. 

In my experience, air is likely to be caused by a rusted through pick-up 
tube or something else in the tank. Thinking about it, I guess that a 
loose connection anywhere on the low pressure side (suction) could suck 
air, and still not leak gasoline. I kind of envision a rubber hose 
connection acting as a flapper valve and letting air in, but not gasoline 
out.
John H.