Scottd

My 72 big block has a metal overflow tank. When the car is cool, I always open the cap and see that the water seems low. (just peeking over where the elbow meets the can. ) I filled it today and found it pissing all over my driveway after a short drive. What is the correct visual level in this tank? Did I hook something up wrong? (overflow hose is hooked up to the topmost port ,just below the fill cap.

markids77

You just need to be able to see "some" when cold. As the car warms up the level in the tank will rise some so filling it all the way cold left nowhere for the expansion from the radiator to go hence the overflow.

MakoJoe

If the tank is dirty it helps to remove it than clean it up after many years and add nice clean fresh coolent to it. I would think it should be about half full when the engine is hot. This what the line on the plastic tanks have and about 1/4 full when cold. Easiest way to measure is with a wooden Dowl Rod or just a piece of wood so you can measure the level without eye balling it.

Scottd

Well, thats not real precise but its exactly what I was thinking. With no view windows, Im limited to looking at the level cold.....but the 'just see some' seems to be the perfect amount without pissing all over the road.
Thanks.

Mike Ward

First- it's not a recovery tank, it's an expansion tank. Big difference.

It puked on the ground because the system was overfilled and there was not enough air space in the tank to accommodate the expansion of the coolant as the engine warmed up.

Since it's no longer puking, it's at the right level. Leave well enough alone.

john 72-04

Exactly...well said.