No the coolant does not actually flow through the radiator if the
thermostat is closed, but the water pump will pressurize the radiator
pushing the coolant through the bleeder if it is open. The tank feeds
the pump inlet so the coolant going in has to go somewhere. You do need
to rev the engine to around 2500 rpm to get enough pressure to fill the
radiator due to its height. Now the heating system is separate some what
from the radiator. When the thermostat at is closed, the available flow
for the heaters is increased. The t-stat does not restrict the flow to
the heaters when the engine is cold. The t-stat does function as a
mixing valve. Coolant is always flowing through the engine and heads.
The t-stat has two disks. As it opens the top disk, the lower closes off
a bypass. Continuous coolant flow keeps the engine temp even and the
mixing action prevents sudden temp changes.

Dennis

-----Original Message-----
From: Ben McCafferty [mailto:ben@kbmc.net]
Sent: Monday, March 11, 2002 11:02 PM
To: Dennis Haynes
Subject: Re: Bleeding the Coolant system

I may be starting to get the picture.  Are you saying that the coolant
flows
up front whether the thermostat is open or not?  And when the thermostat
opens, the hotter coolant from the engine mixes with the cooler stuff up
front, until the temp drops again?  I think I have an incorrect basic
assumption, because I thought the coolant in the front lines/radiator
didn't
move unless the thermostat was open.  ???
bmc  :)
"Faith will move mountains, but you'd better bring a shovel...."

> From: Dennis Haynes <dhaynes@OPTONLINE.NET>
> Reply-To: Dennis Haynes <dhaynes@OPTONLINE.NET>
> Date: Mon, 11 Mar 2002 22:40:08 -0500
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Bleeding the Coolant system
>
> The heater system bleeds itself readily. For best flow to the front
> heater and the radiator, the two hoses should be isolated, not
connected
> together.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
Behalf
> Of Eric Unrau
> Sent: Monday, March 11, 2002 10:20 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Bleeding the Coolant system
>
> Last week, in an attempt to remove the smell of coolant from my '89
> Westy, I:
>
> 1) removed the rear heater
> 2) spliced the coolant hoses together with a copper plumbing elbow
> 3) removed the bed/bench and cleaned up all of the leaked coolant
>
> So far, so good.  No leaks -> no smell.
>
> Here's my question.  In the process of removing the heater, some
coolant
> was lost and therefore some air entered the system.  Do I need to
bleed
> the system?  How would I know if there are any air bubbles trapped in
> there??
>
> Thx
>
> Eric
> '89 Westy
>
>
> ~~~~~~~~~~~~~~~~~~~
> Eric Unrau
> eunrau@yahoo.ca
> ~~~~~~~~~~~~~~~~~~~
>