Engine Cooling system leak

Feb 23, 2013
6
Beneteau First 47.7 Portorose
Hello From Slovenia...

I have beneteau First 47.7, engine Yanmar JH4 series... 78HP....Engine has like 2700 hours, everithing is ok as long as the motor is runing. At this point there is no leak of motor coolant fluid. As i turn the motor off (normally after few minutes on minimal RPM to cool down) ther is also no leak... but after several minutes or maybe an hour ther is a small leak, few drops or maybe sometimes a little more in the back part of the motor (around drain pipe at the turbo). Last year we have changed the mixing elbox part, i have checkd all pipes but i cannot find the spot where the fluid is leaking....

Can some one help me out?


Thanks in advance

Evgen
 
Sep 26, 2008
566
- - Noank CT.
Try a pressure check on cooling system. I am assuming it is the closed cooling side of the system leaking since you said "motor coolant" and not the raw water side but most leaks will show up under pressure. May be something as simple as needed a double clamp on hose or at 2700 hours on engine you may need some new hoses (may not be a bad time to do some pre maintance and replace all hoses)but a pressure check of system will show leaks.
 
Dec 27, 2013
1
Catalina 36 MKII Atlantic Highlands
Wish I could offer some help, but I have a 3GM Yanmar and have a similar type of leak, the source of which I can't find.
 
Jul 28, 2012
35
Catalina 27 Annapolis
A UV flashlight might help. Antifreeze fluoresces under UV light. It's interesting what one finds in the engine compartment. Make sure it's as dark as possible

Josh
 
Feb 26, 2004
23,047
Catalina 34 224 Maple Bay, BC, Canada
I thought they invented paper towels to find engine/hose leaks. :)