Just install one of those aftermarket tanks. Then a clogged vapor recovery system becomes obvious as the tank simply collapses to compensate for the lack of air getting in. BTDT more than once. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Neil N
Sent: Sunday, November 30, 2014 1:08 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Fuel pump/filter

This is just a working theory and kind of far fetched but......

IF the evap system was blocked, would the fuel pump then create a vacuum and cause the pump to cavitate? If so......

IF the evap system had been leaking at an expansion tank(s) or elsewhere but the evap system gets sealed up (repaired) would this revealed a blockage in the evap system in the form of pump cavitation noise?

The last time I had my fuel tank out, I noted that one of the black nylon evap lines had been pinched between tank and frame. Image looking up at fill neck hole: http://tinyurl.com/pfpe82d

that hose runs to the charcoal canister. IIRC, the black nylon line to the evap rollover valve got messed up so I ended up shortening that line a little. I think this pulled it up putting it in a position between tank and vehicle frame.

Neil.

On 11/30/14, Geneva Saint-Amour <genevasaintamour@hotmail.com> wrote:

> Hey listers. We are in sunny Baja MX and thought we would toss this 
> out for discussion.
> Some time ago we replaced the fuel tank. At that time we moved the 
> filter to post-pump location. All was great and quiet.  About a month 
> ago we replaced the seals on the expansion tanks. Now the fuel pump is 
> making quite a bit of noise.
> Thoughts or suggestions are welcome!
>
> Geneva and/or Mike Saint-Amour
> www.slowcarfasthouse.com
>

--
Neil n

Blog: Vanagons, Westfalia, general <http://tubaneil.blogspot.ca>

1988 Westy Images <https://picasaweb.google.com/musomuso/New1988Westy>

1981 Westfalia "Jaco" Images, technical <http://tubaneil.googlepages.com/>

Vanagon-Bus VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>