Coolant replacement

[Derek Rowell]

This weekend I have to replace a fresh water coolant hose, so I might as well drain and flush the whole fresh water side. My yard service manager said that I should use the new red anti-freeze instead of the old green Prestone type. He said that Yanmar is recommending this. Does anybody know what the difference is between the two? I have no experience with the new type.

 

[Mark]

Red vs. Green

The red anti-freeze is now recommended because it was determined that the green will leave an insulating film on the heat exchanger walls if you have an extreme overheat. It takes an extreme overheat - if you shut down your engine or correct the problem soon after getting the high temp alarm you don't have anything to worry about.The one thing you need to be careful about is completely flushing out the old green antifreeze. I forget what my mechanic said would happen if you mixed them, but it wasn't good.

 

[Al Miegel]

red stuff, green stuff

The difference isn't just the color. It's either ethylene glycol or it's propelyene glycol. You might want to consider using Dexcool or some other low phosphate extended use ethylene glycol based coolant if you currently are using "green stuff". Dexcool and others are red but not propylene based. Both ethylene and propylene are clear in nature and dye is added. Propylene is less toxic but doesn't work quite as well as ethylene for freeze and overheat protection. Generally ethylene are green, but can be red (GM, Toyota, Some Isuzu all used red ethylene at some time).

 

[Steve Dion]

Yanmar recommends Texaco Extended Life Antifreeze.

Yanmar now recommends the use of Texaco Extended Life Antifreeze. It is Ethylene Gylocol based too. The difference is really the additives.http://www.delanet.com/~pparish/antifreeze.htm