Looking for Procedure to change Engine Coolant on Yanmar 4JH4E

[andyschoenb@gmail.com]

I am looking for a procedure for the 4JH4E, the maintenance manual only discusses the adding of coolant and not the replacement.
I know there are 3 valves:
1. Below the coolant pump on the front of the engine
2. On the side of the engine aft of the fuel pump
3. At the back of the engine below the heat exchanger
But, I do not know exactly what they look like and how to ensure that air is not trapped in the system. There has been some discussion that if air get trapped in the system it could overheat the engine.
Pictures and procedure would be very helpful. Also, since the coolant in the engine now is GREEN, are there any suggestions on which is the best GREEN coolant to use.
Thank you

 

[marcham]

Do you have a water heater? If so, all the coolant in those hoses also need to be flushed. I use 2 buckets, an electric pump and some custom made adapters to flush out the old coolant.

You should not have green coolant in a yanmar. Blue or Red (normal). It will need to be flushed out with water.

https://www.c320.org/filemgmt_data/files/yanmar_bulletins.pdf

It might be worthwhile to buy a service manual and pay a mechanic to help you do it the first time. Overheating is the main risk of doing this wrong and that could be a costly mistake.