[MR2] MK1 Coolant Problem

[Kurt Krueger]

The real strange thing is that I'm not loosing any coolant when the quantity in 
the overflow tank is considered. It just doesn't get sucked back into the system 
when the engine cools down. That means some place there is a one-way leak, no 
> leak under pressure but a leak with a vacuum when the system is hot. 
>  
> Dennis

I don't remember everything that's been said, but I don't recall that
you've tried a vacuum gauge on the overflow hose.  Plug the hose
with the gauge and a good system should show a healthy vacuum
when cool.

What do the rubber hoses look like when the engine cools?  I've had
some engines where the hoses would collapse completely under vacuum.
Then, finally, the system would draw fluid back from the overflow
tank.

I can't remember, but are there some rubber hoses running under
the car to the radiator?  I know they're metal at the drain
plugs, but don't remember what the rest looks like.  If there's
rubber down there, there's probably enough volume when
collapsed to make up for the coolant that went into the
tank.