Coolant System Green Goo

[cmillsap]

For the benefit of our other readers, just a few more comments about changing coolants from the standard green coolant to ELC (OAT). It is a difficult process to remove all the existing coolant from our systems in these converted coaches before adding the new coolant. It is said that mixing one with the other is not detrimental except that you lose all the advantages of the ELC. I agree with that to a limited degree. I think that topping off or adding a gallon or so of ELC to the standard coolant (or vice-versa) doesn’t hurt anything. But adding ELC to a system with a large amount of standard coolant remaining in the system and auxiliary circuits found on our converted coaches is not good. I relate it to the same as mixing different motor oils in the engine crankcase or mixing different fluids in the transmission. It’s just not a good practice. Listed below are the color codes depicting coolant types.

David,

Since you have already been through two previous coolant exchanges and this time you flushed your system really well with water before installing the ELC. And with changing to the blank filter, you should be in fine shape to take your trip. The green film may just go away by the time you get back home. If you find that the film is no longer or less in your deaeration tank, odds are that it is gone from inside your transmission cooler. If your transmission temp stays in the acceptable range while you are on your trip, it may not even be necessary to flush your system or take apart the cooler to clean it.

Antifreeze/Coolant Type TMC Spec Suggested Color Code
TMC A—Conventional Low-Silicate RP 302A Green (PMS #374-376

TMC B—Fully Formulated Ethylene Glycol RP 329 Purple/Pink (PMS #235-241)

TMC C—Fully Formulated Propylene Glycol RP330 Blue (PMS #29301)

TMC D—Organic Acid Technology (OAT) Per OEM Specs* Red (PMS #190-193)

*-OAT coolants are defined by the product meeting one or more of the following manufacturers:
• International—Class 8, B-1, Type III
• Detroit Diesel 7SE298 9804
• Caterpillar EC-1
• Mack 014 GS 17009