The water pump, radiator, all coolant hoses, thermostat, coolant temp
sensor (on the thermostat), fan speed switch have all been replaced on
my van.  At each procedure (some of the jobs were done together), the
air bleeding was done with all four wheels on the ground.  To the degree
that the cooling system has air in it, that is only because the heads
seep when the engine is cold, and so I have had to add coolant
periodically.  Actually, I have not let it get low enough for the
expansion bottle to be low, only the overflow bottle (the one behind the
license plate), so I don't think any air is getting in.  For better or
worse, the head seals will be replaced next week.  I suspect that the
coolant will be drained, replaced after the job is done, and the system
bled with all four wheels on the ground.  DMc

On Wed, Dec 30, 2009 at 8:54 AM, george jannini wrote:

>>> Not sure why so many think you can bleed the water boxer any way you
>>> choose. ...
>   Because you can-  I've seen it done, and participated in the
> perpetration.
>   I couldn't convince the "Joe's Garage" mechanic who replaced our
> water pump in Cody, Wyoming that it was necessary to raise the front
> of my bus to effect proper bleeding, so we did it his way, on the
> flat.
>
>   His instincts were correct, the job went well, and I went on my
> merry way, bound for San Francisco.
>
>   Being that this all happened 14 years ago, and I'm fricken' old, I
> misremember whether we needed additional coolant over the course of
> our trip, but I don't think so.
>
>   I do remember, though, that "Joe" had more than a few choice words
> concerning said replacement of water pump.
>
> George & Jo/ATL