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Re: <small-six block coolant....> tech tip

In which Eric replied to my previous post:

>>From Paul Reitz, digest 5 #152:
>...
>>What I meant to say was that you should add all the antifreeze required
>>*first*, then fill the system with water, since you can't tell exactly how
>>many quarts, total, you'll be able to get back in.
>...
>It is _much_ easier and far more accurate to dilute the antifreeze with
>water prior to filling the cooling system. I keep a few empty spare
>antifreeze containers around in order to do this. Plus, your leftover
>antifreeze is at the proper dilution in case you have to top the
>cooling system off.
>


Yes, I agree, Eric, but you missed the point.  I had always done this on
previous vehicles (all BMWs), but the E30 system seems to be peculiar in
the amount of coolant that remains after draining.  So if you dilute the
antifreeze to the expected required concentration, then find that you can
only add 9 quarts (instead of nearly 12), you now have only 3/4 of the
antifreeze required, and no way to get more in without draining something
out - likely, some of it the antifreeze mixture you just added.  (Assuming,
of course, that you had actually flushed the system with water before
adding the antifreeze, which was my premise....)

While it may be easier to pre-mix, it is no more accurate, and, under the
conditions described above, is not even sufficient.  Besides, it probably
takes all of 5 minutes max after warm-up to thoroughly mix the antifreeze
and the water you used to top up the system.  A completely agree with your
comment about keeping the remainder pre-mixed.

So my question remains: can anyone recommend how to evacuate the entire E30
coolant system so it would be possible to add a pre-mixed solution?

- -Paul Reitz
BMWCCA #1167