Date:         Thu, 5 Oct 2000 09:46:16 -0400
Reply-To:     psheridans@NETSCAPE.NET
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         M Kaz <psheridans@NETSCAPE.NET>
Subject:      Re: Hanging flaps in heater box
Content-Type: text/plain; charset="ISO-8859-1"

Hi All,
I am right now working on my heater box and was wondering if anyone knows where I can get replacment brushes for the blower fan? I figure since I'm in there I might as well do it now while its out. Also has anyone replaced any of the foam flap seals? mine are shot, and I was wondering what others have used .
TIA
Mark K.
> ------------------------------
>
> Date:    Wed, 4 Oct 2000 15:44:30 -0400
> From:    David Beierl <dbeierl@ATTGLOBAL.NET>
> Subject: Hanging flaps in heater box
>
> Ok, I understand what the free-swinging flaps do in the heater box.  They
> matter...
>
> Heater box has three functional parts: cold air inlet, cold air plenum, hot
> air plenum, arranged top to bottom.  The blower is the obvious connection
> between the inlet and cold plenum, but VW added two big holes (about 3x6"
> each) so that ram air wouldn't have to pass through the blower to get into
> the plenum.  But now of course the blower output is short-circuited right
> back to the input; so they added a couple of very light swinging flaps that
> close off the holes whenever the pressure is higher in the plenum than in
> the inlet.  The design (if you can call it that) of the flaps is such that
> they ordinarily fail open, either by sticking or by falling off.  Either
> way, result is that you get greatly reduced blower output.
>
> The flap design is bad because they made the wearing parts out of plastic,
> and doubly so because the pins on the flaps hang from the open ends of the
> little clips they're stuck into instead of from a solid part.  So as the
> pin gets smaller, the opening also gets wider until the flap falls off.
>
> Fixes -- 1) new middle section (that's where the hinges are) and new flaps;
> 2) build up the pin thickness with epoxy -- it's unlikely to have broken
> off completely -- and make new hinges.  This is hard because there is no
> access.  I succeeded by heating brads and driving them through to support
> the pins, but it's still hard; and you have to remember to put the flap in
> before the second hinge since it no longer snaps into place; 3) in a pinch,
> close off the holes permanently.  This will reduce the flow of ram air
> because it will have to pass through the blower, but it's better than nothing.
>
> These flaps are covered with light foam (easier than putting a narrow strip
> on the edges) but I see no need to renew this as it mostly reduces the
> noise of the flap hitting the frame.  As long as there aren't lumps
> standing up in some places and not others, there should be no functional
> difference.
>
> david
> ps -- we might consider a contest for how far someone can send one of the
> spring clips that hold the box together -- and still recover it.  They're
> snappy little guys, pays to hold your finger over them whilst
> removing.  Did I hear they're close to $4 each at the dealer?
>
> pps -- I would strongly recommend replacing the M6 screws holding the
> heater box to the vehicle with M6 bolts instead, and generously anti-seized
> at at that.  This is an area that takes a hit when the windshield leaks,
> and the ends of the upper four screws/bolts are out in the open
> anyway.  Might similarly replace the Phillips screws on top of the dash
> with hex-head screws as they are quite difficult to drill out with the
> windshield in place.
> David Beierl - dbeierl@attglobal.net <<- New address becomes mandatory on 1
> Oct, optional until then.
>
> ------------------------------