Coolant

[gonesailing13]

Have a Ford Lehman on our boat. The previous owner had always used the green Prestone antifreeze in the engine. I’m going to be flushing the system out and am wondering if I should be using the orange coolant I see that’s for Ford ? If I switch how well do I need to flush the system. Am guessing you can’t have any mixing of the two. I guess my question is green or orange ?

 

[RT Firefly]

Greetings,
Mr. g. I use purple. Hahaha....Seriously, I purchase 50/50 premixed DIESEL anti-freeze from NAPA. I think the "brand name" is Fleetguard. Yep, evidently there is AF specific to diesels. Something to do with cavitation bubbles along the cylinder walls of some diesels (I don't know if the Lehman is one of those but I use it anyway).


As to flushing???? I have no idea. 2X, perhaps? I think you are correct about not mixing different types (colours).

 

[Comodave]

We had SP225s in our last boat. I asked Brian at AD and he said it really didn’t matter so we used some kind of Zerex.

 

[Cigatoo]

You can use either. Green / yellow or the extended life red / orange. If using the extended life be sure to flush the old coolant out of the system well with fresh water 1st. You can’t mix the extended life with the old green / yellow. Best to mix new coolant of either type with distilled water to eliminate minerals. Cavitation issues were an issue with the high horse power to displacement diesels. Yanmar being the most common. Those engines require the extended life coolant to eliminate the cavitation issues.

 

[Bacchus]

Good idea to use fistilled water for the last flush.