I am having an issue with a coolant leak on my 2001 Beaver Contessa with a 3126B CAT engine. Last January the radiator and CAC were removed from the coach when I had a cracked fan replaced. The...
My next step would be to run a system pressure test which does not require the vehicle to be running. These kits are available on line (Amazon). Pump it up to 15lbs or whatever the cap is rated at and see what happens. Observe for leaks anywhere. If none visible then and only then would head gasket or other internal leak be investigated.