Best/Worse coolant for M25

[Porchhound]

I can't find it, but somewhere I read a thread regarding coolant(s) to avoid in this engine. I'll be replacing mine so I want to get it right.

[scgunner]

Prestone green (original) been using it since 1988 with no issues.

[Jon W]

Are you thinking of the orange colored Dex-Cool?

[Ron Hill]

porch : Just get the BEST Preston Brand Ethelene Glycol .  Read the bottle and make sure it will mix with any other Ethelene Glycols!!

A thought

[KWKloeber]

I can't find it, but somewhere I read a thread regarding coolant(s) to avoid in this engine. I'll be replacing mine so I want to get it right.

[edited]

Dave

The Dex-Cool (red/pink orangish) is what I think you are referring to NOT use in our engines.

Either an ethyl glycol (green, toxic) or propol glycol (pink, more environmentally safe not as permanent) antifreeze is what you want.  There's message archives on here that speak to flushing and replacing the mix (50% AF - 50% distilled water)  Search for those.  Also check Rod Collins' site -- he may have an article on engine AF.

[Breakin Away]

FWIW, I switched to Zerex G05 a couple years ago. It is a light amber color - not green, orange, pink, or red. It's a Heavy Duty ethylene glycol type antifreeze, with HOA for corrosion protection, and with anti-cavitation additives that are helpful for the high compression vibrations experienced by diesel engines. The anti-cavitation would be critically important for engines with sleeved cylinders, but I do not think that any of Universal's engines have that. I'm not going to claim it's the only one to use, or even the best one. It's just another alternative that you might want to check into.

[KWKloeber]

The anti-cavitation would be critically important for engines with sleeved cylinders, but I do not think that any of Universal's engines have that.

I don't pretend to know why it would or wouldn't make a difference w/ antifreeze but the Bs' cylinders are not lined, the old engines are.