Coolant System Green Goo

[davidbrady]

(07-02-2017 16:23)cmillsap Wrote:  David,

I don't allow anyone to add coolant to my system unless I see and approve it first. I don't understand why Prevost would install an SCA releasing filter when the system is full of ELC??

It's clear these guys don't understand the current crop of coolants on the market. Shame on them for not knowing, and shame on me for not checking. I was new to Prevost ownership and new to the Service Center experience and I pretty much put my fate into their hands. Big mistake.

(07-02-2017 16:23)cmillsap Wrote:  The only reason that I suggested going back to the green ethylene glycol is that it may dissolve the green goo better than the ELC. But if you have already refilled with ELC, lets hope it will not exacerbate the growth of the green goo and maybe it will even dissolve it.

As you know, I'm not a chemist but from what I've read silicate dropout (green goo) is very stable; i.e., inert, and is only produced by standard (green) coolant. ELC coolants have no silicates. It's not likely that any coolant will dissolve it. But, a harsh caustic alkaline rinse with something like Fleetguard's Restore will dissolve and remove it. The trouble I have with this is: in my case is the cure worse than the disease. Prevost's maintenance guide is very thorough. They only flush specific elements and they backflush; i.e., with reverse flowing water and bursts of air pressure. Check out the manual attached below. They backflush the heat exchangers and the engine, and that's it. Plus, they only do it if the engine is experiencing overheating! Mine isn't! These products like Restore need to be kept in the coolant system for a minimum of 2 hours and a maximum of 3. They attack soft metals and elastomers (silicon hoses) and who knows what else. I don't care if I have a film on my hoses, but I don't want a film on my radiators or inside my engine. I think the best I can hope for, as far as coolants sweeping it away, is the natural tendency of fluid flow erosion along with the loosening effects of heat and vibration, basically mechanical scrubbing. For instance, I can't imagine a microscopically thin film lasting long on an S60 cylinder liner! I think if I take it apart and find my transmission cooler to be absent of film, then I'm good to go.