Heater water flush

[BROAD REACH]

It is that time of the year to flush the fresh water cooling system on my Yanmar 3GM30F.
There arre two cooling holses on top of the engine - one of which ends at a point just below the thermostat. The other hose seems to terminate at the engine driven water pump.
My question is: on which hose do I install the flush water feed to the cooling loop ??

 

[Alan]

The short answer, either one. The cooling system is a continuous loop. It can be interrupted anywhere in the cycle. I am fortunate to have an automotive cooling system flush machine that does the job of flushing and refilling automatically. I would suggest that flushing your cooling system is a great idea but I don't think you need to do it annually. Even every other year is more than sufficient maintenance interval.

 

[kloudie1]

Water Flush

My tee flush fitting on the 3GMF is in the line going to the heater from the thermostat housing. You can see the little black cap on the tee just to the left of the coolant overflow tank mounted on the sidewall. On the aft most hose on my engine; put there by the P.O. I agree that it doesn’t have to be done every year, especially if you keep good long life antifreeze in it. Every two to three years is fine, when you change the coolant. I also agree that it doesn’t make a whole lot of difference which hose it is in but ya need to drain the block and exhaust manifold, using the petcocks, before you start to flush.