Last week I changed the bypass hose on my Girlfriends 3100 engine.

There was definitely a hole in that hose, but there is a leak just
underneath the lower part of that hose.

There is a "rail" that runs horizontally across the engine and connects to
the bypass hose via a connection that also makes a turn and goes into the
engine block.  The leak is at the juncture of the vertical part of the rail
and the engine block.

What is this rail and is there a fix for this part of the coolant path? A
new gasket perhaps?

As the weather heats up, the coolant is being lost pretty fast.

Thanks for any input.

Matthew