Bolster froze

Radiator was off and bolster was drained but filled up with water before freezing teperatures set in. Mid twentys over night and day time highs of 33 deg. Not all that much of a loss. Look to the right of the fracture and you will see a one inch wide braze from a prevaious break. Bolster is not all that thick of a casting from what I can see at the break. This is on a 48 cub. did they beef up these castings in lator years?

You would have though that it would have expanded upward. Newer is better :wink:

Probably froze over on top first, and anchored itself into that casting. It is a bit surprising.

Yep Like Boss says, newer is better. Take a look at the front casting on the engine (the famous ear) on your Cub and then your Lo Boy. They beefed both castings up considerably along the way.