Luck smiles upon you!

List: I'd like to better understand what David did.

On 6/26/2006 3:32 PM David McCallum wrote:
> ... I could hear the
> coolant boiling in the engine, the expansion tank was half empty, and the
> overflow tank was completely full and leaking precious coolant.
So what happened here? Coolant had blown out the pressure cap on the
expansion tank into the overflow (refill) tank, yes? When he got to it,
no more coolant was trying to force its way out, and there was a big
bubble at the top of the expansion tank.
> I carefully
> removed the overflow tank hose and slowly opened the expansion tank
> pressure
> cap, hoping to depressurize the system to avoid damage and more boiling.
Wouldn't keeping the pressure high reduce the chance of boiling? Would
you want to just let things cool down?
> Filled the expansion tank from the
> overflow tank using a Nalgene to transfer, put everything back together,
> started the bus (so far so good), opened the radiator bleeder (wife
> revving
> the wasserboxer to 2k RPM) to make sure there wasn't an air/steam
> bubble up
> there, let it idle for about 10 minutes. No leaks from the heads and
> hoses,
> no bubbles apparent in the cooling system, we headed back out on the road.
Lemme see if I got this right. By moving the fluid from the overflow
tank back into the expansion tank by hand, David topped off the cooling
system. Air bubbles are bad. He opened the bleeder value on the radiator
(behind the headlight grille), his wife revved the engine, and if there
were bubbles up front, air/steam would blow out the bleeder as the
system pressurizes. If coolant squirts out, close the bleeder. Keep the
engine running, look for leaks, eyeball the expansion tank for bubbles .
. . cross fingers and drive?