955k trans cooler leak

I have a 955k 85j serial # i recently purchased. I have a leak at the bottom of the trans cooler above the flange of the lower tube assembly where it mounts to the trans cooler. I originally thought was leaking at the flange but after cleaning up and starting cold i could see where fluid is coming out. Fluid is coming out "foamy". The trans cooler in pretty dirty inside engine bay. I had Cat send diagrams and noticed i am missing the relief valve assembly also.

Thoughts on cause and way to fix. Hole in cooler core?