Date:         Sun, 14 Mar 2004 12:07:23 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: fuel filter: before, after, indifferent?
Comments: To: "Phillips, Andrew" <phillips@ISGS.UIUC.EDU>
In-Reply-To:  <537CB9DDD9077549945D568618BDCA0B2050A8@isgs1pdc.isgs.uiuc. edu>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 12:00 AM 3/14/2004, Phillips, Andrew wrote:

>The fuel filter is positioned after the pump.  A note with the fuel pump I
>just installed (related message is elsewhere on the list) read that the
>filter should be replaced regularly to protect the pump.  If the filter is
>after the pump, how can it possibly protect the pump?  How many of you add
>an additional filter between the fuel tank and the pump?

Some Vgons have a small squarish plastic filter before the pump; some have
a large metal can after the pump; a few may have both.  IIRC the pump is a
vane pump and can probably pass a certain amount of small trash without
damage; but it's absolutely essential to keep the fuel going to the
injectors pristine.

The filters before the pump give warning when they start to clog because
they cause the pump to cavitate which makes it considerably louder than
normal.  The Bosch pump is btw noticeably quieter than the smaller-diameter
aftermarket replacement (I forget the brand; reputable maker, I think they
supply Mercedes).

With engine off I can hear the brief initial pump run through the
floorboards.  With engine on I can't hear a thing.  With a clogged filter I
can hear it over the engine when idling.

david


--
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"