bleeding the coolant

[shorebird]

Since our hot water tank seems to have turned into a pile of rust over the winter, I am in the middle of replacing it. I will be using the engine heat ports to heat water while the engine is running, and the installation manual says to bleed the engine coolant, but I have no idea how to do this. Once the whole thing is hooked up, I will have to top up the engine coolant, but how would you remove air from the Yanmar's closed fresh water/anti-freeze mix?

[gamayun]

When I cleaned out my heat exchanger, I just popped the hose from the front and drained if from there. It's hazardous stuff so dispose of it properly. Then, I just filled up the 50:50 coolant at the top where the cap is located. I have an overflow tank, but the fill level stays at low so that when the coolant heats, it slightly fills up that tank. That's it. I did not need to bleed the coolant side. Would be interested to hear if I should have done anything differently. My engine is a 3GM30F.

My hot water tank is completely out of the picture now, too, because it rusted out and I need to replace the heater element. I have closed off all the hoses so the engine water heat cycling doesn't run through the water tank any more.

Hope this is helpful.

[delmarrey]

Don't know about yours but the newer Yanmars have a couple brass bleeder valves on the front of the motor up by the thermostat with a nipple on top to put a hose.