There is a small 90 degree hose that attaches to the back of the thermostat that is a pain to get to but it leaks and is almost impossible to pinpoint. Also it connects to a metal pipe that goes all the way around the motor, the pipe sometimes rusts and leaks. In this pic it is just below the cps its the rusty pipe with the hose below in on the right side middle of the pic. The hose is already off the pipe in the pic.
