Someone on the list recently suggested it was because, in many cases, the
rear heater never gets shut off. You have to lift the seat  and reach in and
turn the lever and remember which way is off or on. I used an indelible
marker on top of the housing to remind me.
Jerry
----- Original Message -----
From: "David Luddy" <bugle@EPIX.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, December 17, 2000 3:23 PM
Subject: heater core questions

> hello all.
> happy seasons greetings!
>
> Why is it that the front heater cores seem to have no problems?
> I've examined the front and rear heater cores from one of my parts vans
and
> they are both made by the same french manufacturer. Both are the same
> construction and materials, they are even the same thickness. they both
> appear the original units, the rear is extremely corroded at the bottom
> both sides at the steel crimp that holds them together. The front core
> looks fine, as if it was getting different "long lasting
> anti-heater-core-corrosion" fluid run thru it.
> Is it just that the rear gets less circulation? Or could it be that it
gets
> hotter fluid thru it? I plan on modifying a rear housing to accept a front
> core and front valve ( my typical cost saving measures... use it till it
> breaks!)
> I figure the only drawback is losing some under bench storage space.
Anyone
> gonna tell me some words of wisdom why I should shell out the $100 for a
> new correct core?
>                       thanks
>                                David
>