Flushing Anti Freeze While on Trailer

[Gratitude]

It is time to replace coolant on my Yanmar 110. Can I flush the coolant the same way as the car. Open the drain cocks and let coolant run out. Run fresh water into the fill cap while engine is running until fresh water starts comeing out the drain cocks. Close cocks refill with antifreeze. Run engine. Check level. I will be doing this on the trailer while running a hose into the sea strainer at idle.

Any tips appreciated. I can't afford to waste a drop of Yanmar Antifreeze.

 

[Levitation]

Assuming the coolant is a couple of years old, I question the benefits of any flushing...
My choice is to drain the block and radiator...
Refill with fresh...
Run engine a few minutes and shut off and drain a second time..
Refill with fresh coolant...
Done....

In a long life I have owned several businesses including auto and truck repair... Learned a lot about the predatory behavior of name brand manufacturers... Yanmar is making a huge profit on their branded coolant - I don't like being taken...

ALL antifreeze for engines is Ethylene Glycol mixed 50:50 with water... The only difference between the types is the anticorrosion and lubricant additives...
Green (traditional Prestone, etc.) colored antifreezes are considered good for 2 years / 24000 miles... It contains silicates, and other chemicals to work it's magic...
Extended Life / Long Life antifreezes contain Organic Acids for the anticorrosion p;us the usual lubricants... They can be rated as long as 5 years / 150000 miles...

I can recommend the following long life / extended life coolants as having been found excellent for use in diesel engines by diesel engine remanufacturers I dealt with...
Texaco Long Life Coolant and anti-freeze #7991 (premix is #7998, but again you are paying $3 a quart for water)
Havoline Long Life Coolant and Anti-freeze # 7994
Dex-Cool Long Life - any GM dealer or auto store
Prestone Extended Life...

Now, having said all this, I maintain a number of engines, diesel and others, and I normally use plain old green coolant and change it every two to three years (depends on the running hours - my classic tractors only run 5 to 20 hours a year so 3 years is fine)... I have not had a coolant related problem in 50+ years...
My tug is due for fresh coolant this fall... It will not be one of the organic based, long life coolants (i.e. orange color)... It will be Green... YMMV

 

[Levitation]

Oh yeah, and I forgot to mention that Cummins does not recommend orange coolant in their diesel truck engines as it is hard on some of their gaskets...
Be aware the internal metals on marine diesles and truck diesels are the same...

 

[needatug]

Hi All

I've been following this site for years and when the economy and my finances come to terms I will be buying a Tug. Until then I follow along and wish. This however is an issue dear to my heart and I agree completely with Levitation. I have maintained every motorised contraption I have ever owned myself and have never bought the manufacturers reccomended (there brand name) products. Frankly I just feel like I should get a kiss if I did. I do have to confess although I change oil frequently and consistently I never have intentionally flushed coolant. I have added or topped up after a hose or rad leak but as I've been in the work force long enough to have newer vehicles that has not occurred in years. What I see is that all boat engines are from vehicular adaptations with marine compliant bolt ons to solve corrosion and reduce risk of fire. The latter of which seems to be well in hand in that I have seen more burning cars than boats in my life. With regular oil changes and clean fuel I would not be worried about the engine. As for all the other creature comforts on boats I would expect them to self destruct at inconvenient intervals. :lol:

My two cents worth (which has withered to less than that)

 

[Gratitude]

Thanks for the replies. Everyone I know who knows about engines is in agreement about name brand being more about $ than effectiveness and that the change intervals are real aggresive. My concern is in the first year of my boat's use I had my heat exchanger gum up. Hatten Marine claimed it was because I was using the wrong kind of antifreeze. They removed the heat exchanger, boiled it out, replaced it and put the extended life antifreeze back in. I have not had a problem sense. So that experience has caused me to take into consideration name brand and honoring the prescribed maintence schedule.