> The bad news is that I have bad stuff coolant in there (86 Westy)!
AAAArrgh.
> It's been there since last summer.
>
> Any advice? Dump the bad stuff and risk another air pocket, or keep the
bad
> stuff?

Would you rather have leaking head gaskets AND the blinking light???
Don't be silly... get the bad stuff out of there... you should be changing
coolant every 2 years anyway so it's either not or next year anyway... just
do a better job of bleeding the air out and if you haven't replaced the
coolant level sensor lately... do that too.
Just another opinion.. :)
Bill