I prefer to err on the side of more maintenance than not enough...
�
Having said that, crud from your tank and the gas fills that have been done over the years, having a pre filter is a good idea to protect the pump...BUT!
�
1) if the pre filter gets plugged it starves the pump and you can't see it through the shell...take yours out and open it very carefully to view contents...if it's full of crud, start replacing it more often...FRAM has a clear one that makes keeping an eye on it easier.
�
2) kind-of funny how the metal (expensive)after filter still lets injector plugging crud through, particularly rust...
�
IMHO...use both
�
Den.

>________________________________
> From: Troy <colorworks@GCI.NET>
>To: vanagon@GERRY.VANAGON.COM 
>Sent: Monday, February 20, 2012 4:05:13 PM
>Subject: gasoline prefilter
>  
>Hi folks:
>
>I have an 89 vanagon westy. I have a square prefilter before the main canister fuel pump, and I'm told this is not a stock set up. I have also read in various posts how rust/sediment in the tank can get lodged in the fuel pump, so wondering if I should just leave the square prefilter in place when I replace my fuel pump. Is there any harm to doing this? It apparently has been working fine for years this way.
>
>Troy
>
>
>