Date:         Thu, 20 Dec 2001 02:46:43 +0800
Reply-To:     Tim Hannink <tjhannink@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tim Hannink <tjhannink@EARTHLINK.NET>
Subject:      Re: Coolant Service Procedure
Content-Type: text/plain; charset="iso-8859-1"

Are you draining the system when the engine is at operating temperature? If you are, your method will work well provided the thermostat is open, but if not, consider this:

How are you draining and flushing the coolant out of the hose that runs between the thermostat housing and the radiator? Blowing air into the radiator bleeder can't push the water toward the motor because the thermostat will have that end of that hose closed. It can't suck the coolant out of the hose for the same reason. You can't push water from the overflow tank to the radiator through that hose either. Some coolant may flow through the automatic transmission cooler to the coolant distributor, but there is no alternate path for a manual transmission vehicle.

By my calcuations that particular hose holds .9 gallon of coolant (1.25 i.d. x 12') plus whatever might remain in the radiator. That means that at least 20% of the coolant will not be flushed out of the system.

I would recommend either removing the thermostat or opening the radiator-to-thermostat hose to drain the cooling system more completely.

Tim Hannink
Goldibox - 1987 Vanagon Camper, Wolfsburg Edition
Winter Park, Florida
http://home.earthlink.net/~tjhannink/




-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
Of Doktor Tim
Sent: Wednesday, December 19, 2001 11:19 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Coolant Service Procedure


This is the coolant renewal procedure I use for Wasserboxers. It takes me
1.5 hours typically. You will need a GOOD jack and a pair of 6 ton jack
stands.

Raise the rear. Remove lower cylinder covers and head drain plugs. Lower
the rear, raise the front, remove the pressure cap and radiator bleed
valve. Let drain. Blow low pressure air through the radiator bleed valve to
push the remnant fluid back to the motor drains. Lower the front, raise the
rear so the pressure tank is higher than the radiator bleeder bolt, the
higher the faster the flow. Reinstall the motor drain bolts for temporary
flushing. Pour water in the pressure tank until clear water runs from the
bleeder hole.

<SNIP>
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