Date: Tue, 13 May 2003 20:31:40 -0400
Reply-To: Dennis Haynes <dhaynes@OPTONLINE.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <dhaynes@OPTONLINE.NET>
Subject: Re: Coolant air - prevents fan?
In-Reply-To: <196.1a4de012.2bf2da3e@aol.com>
Content-type: text/plain; charset=us-ascii
The bleeding has to done before the engine warms up. Once parts in the
engine get near 140F, the water will vaporize with the system not sealed
and under pressure. Continuing to bleed a hot engine will result in
damage. I don't bother to raise the front of the van as it only makes it
harder for the pump to fill the radiator. I bleed the system as follows:
Engine stone cold
Make sure all hoses are installed correctly. Direction of coolant flow
does matter.
Open both heater valves
Open t-stat bypass valve
Remove pressure cap
Fill main bottle; keep filling if level goes down, block is filling up.
Get friend to help.
Start engine and hold fast idle, 2,000-2,500 rpm.
Have assistant open radiator bleeder.
Keep main bottle filled, coolant will go down to fill radiator and
heater circuits.
When steady stream comes out of radiator, close bleeder screw.
Top off main tank, install cap.
Allow engine to return to normal idle. (if cap is not on, than coolant
will back flow out)
Close t-stat bypass.
Re-install hose from cap to rear expansion tank.
You should be done bleeding.
Observe operation. Make sure water is flowing to both heaters. If so,
turn them off. This should take less than 5 minutes.
As engine approaches normal temp., make sure water is flowing through
radiator, when radiator gets hot, make sure fan operates.
If water does not flow through radiator, the system may be air locked
again. If so, you need to do some testing of the engine looking for
internal leaks. Small amounts of air will work out after a few warm
up-cooling cycles if the system is healthy. Make sure the pressure cap
is working. If water is not flowing, the fan will never turn on as the
fan switch is in the radiator. The radiator can also crack internally
allow the water to enter and exit without flowing through the core.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf
Of Dustin Fitch
Sent: Tuesday, May 13, 2003 7:31 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Coolant air - prevents fan?
hey all. quick question for ya on my '85 1.9L (no resistor behind L.
Headlight). I bled my coolant system today. Naturally, the air must be
bled. I'm halfway there. The question is: at first, when she heated
up, as
I entered the coolant, the fan came on eventually. Then i bled the
air the
first time.....she got hot...I bled. No fan...neither stage. I got all
the
way up to near the top line on the heat gauge..blinking LED. Then shut
her
down. Bled again....lots of air.....still...no fan. Does air in the
line
affect the fan operation?....even when you've got almost...just
about....all
the air out of er'? My temp gauge has stabilized but I know I still
have
some air...I can hear it bubbling a bit still. Not too bad. But
still....no fan. I don't understand that....I thought if that switch up
front...which is new today and obviously worked once....I thought if
when it
got hot, it puts the fan on, air or not.. Apparently not. Is it the
air in
the line still?
My front end is elevated and the relay for the fan is new too. So isn't
the
fuse. Only thing I've never done is the thermoswitch in the thermostat
housing. I know the thermostat is opening eventually, because I have
heat
and steam at the bleeder valve on the radiator.
TIA
Dustin
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