Date: Sun, 18 Nov 2012 22:38:43 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Rear heater control
In-Reply-To: <D6A721FA-F02D-4E06-83E9-9322BB68C43C@shaw.ca>
Content-Type: text/plain; charset="us-ascii"
Heater cores tend to be made of very thin material. Leaks that are not
caused by leaking end caps or direct damage are usually the result of the
flowing coolant abrading-wearing the tubes to the point that they leak. This
is especially true of vehicles that flow coolant through the heater core all
the time and use damper-blend doors to control temperature. In part
conventional antifreeze used the silica and other stuff to control corrosion
by "cleaning" it.
Since the rear heater recirculates the air in the vehicle it is very
effective at heating the interior. I turn the valve off in summer and then
open it about 1/4 to 1/3 for winter. This provides plenty of heat for the
rear. As the rear heater is parallel with the front any coolant flowing
there is not available for the front. You want a lot of heat up there for
defrosting.
For that white bleed screw if it has not been touched don't. I doesn't take
much for the top to break off and boy can it make a mess as the coolant
system empties into the rear. The rear heater bleeds well enough without
opening this bleeder. If you must touch it replace with a steel M8X1.0 and
fiber washer to seal it.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Alistair Bell
Sent: Sunday, November 18, 2012 8:35 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Rear heater control
"old coolant is terribly corrosive"
come on now, how is coolant that is not circulated any older than the stuff
that is circulated. I call bull-pucky.
alistair
On 2012-11-18, at 1:50 PM, Scott Daniel - Turbovans wrote:
> There is no 'control knob' ..
> there is a lever that you can reach with your fingers, through a hole
> in the rear heater cover.
>
> if the cover is not in place...the poster could be looking at a
> knob-like thing ..the bleed valve.
>
> Bentley would not say much about this leverthat regulates coolant flow .
> but the van's Owner's Manual sure does.
>
> 'Forward' on the lever is 'on'.
> Aftward is off.
>
> I recommend having it at least mostly 'on' all year ..
> as having no flow at all, ever, or for very long periods ,
> contributes to rear heater core leaking ..
> a pretty common thing actually. .
>
> Whether warm air comes out the rear heater is determined by the fan
> for the rear heater being on or not, or course.
>
> you always want at least some coolant flowing through the rear heater
> so some fresh healthier coolant is always going through it ...the
> parts last longer that way. Old coolant is terribly corrosive.
>
> Nobody on this list of course...
> there are lots of vanagon owners that don't know about the heater
> control lever under the back seat.
> I was kinda shocked actually to find out VW did it that way.
> I can't think of one other car that has a partially heater control
> under the back seat.
>
>
>
> On 11/18/2012 11:49 AM, Dave Mcneely wrote:
>> Harry, that control allows coolant to circulate through the heater
>> core. Summer, off, winter, on. To control air flow, use the knob on
>> the dash. mcneely
>>
>> ---- Harry Hoffman <hhoffman@IP-SOLUTIONS.NET> wrote:
>>> Hi all,
>> The heater under the rear seat has a control knob.
>> Can someone tell me what it does? The Bentley only shows a picture but
not how it functions.
>>
>> Cheers,
>> Harry
>>
>> --
>> David McNeely
>>