Is that a D65 EX-15? If it is I hope the pump was your problem esp since you tore it all down. I had the same overheating problem on my dash 15 about a year ago. My problem ended up being a little solenoid type valve that controls the swash plate angle of the fan pump. IIRC (I'm just going off my memory. LOL) When one or both of the controllers senses something getting warm then it sends more electricity to the solenoid which gradually opens a valve that increases the swash plate angle of the pump which makes the fan turn faster. I sold the machine about 6 months ago and let my manuals go with it so I apologize if my terminology is not correct but that is pretty much how the system worked on mine. Like I said I hope the new pump solves your problem. If not I would look into that solenoid valve that I attempted to mark on your pic. Good luck. FWIW I used to lay awake at night if I knew I had to pull the seat out of that SOB the next day!!!! 
