>
> Good/bad idea to release some air by twisting blue expansion cap when
> engine
> is warm?
>

Bad. The air should still be there when the engine cools. Open the cap COLD
and replace the air with coolant. You could let the air out under pressure
when hot, letting the expansion tank refill from the overflow as it cools;
but cold filling achieves the same thing and doesn't have the potential
unpleasant side effect of steam burns.

--
John Bange
'90 Vanagon - "Geldsauger"