Community Forums

RVPioneer · 05-27-2017, 10:02 AM

Old Scout, The blue coolant is Fleetguard ES Compleat EG and is not an OAT coolant. The product names are often confusing or misleading. Definitely a wise choice to have an extra gallon of exactly what was used. I'm still running the green coolant but will be making the switch to OAT when the time comes. Probably next summer. Just had a full service at Cummins, oil, filters, coolant and battery check, lube, etc.

I'll have the coolant flush performed at Cummins as it will eliminate the problem of fluid disposal and reduce the possibility of a calamity in the driveway.

Dudley do-right · 05-28-2017, 02:57 PM

what is OAT coolant? I assume it's an acronym for something, and I'm sure that spells mo' money!

DrDaveMA · 05-28-2017, 07:10 PM

OAT - Organic Acid Technology
HOAT - Hybrid Organic Technology
SCA - Supplemental Coolant Additive

RVPioneer · 05-29-2017, 04:45 PM

Dudley, the OAT is a bit more expensive than the ethylene glycol (EG) based coolants. It also requires a complete flush out of all the old EG coolant, so there will be an additional labor cost at the shop. I've been quoted prices in the $600-650 range at Cummins. On the plus side the service life is up to 10 years and/or one million miles. Typical service life for EG is 2 years. Five coolant changes may cost more than one.

The OAT coolant requires annual checks with a chem-strip to determine proper additive and pH levels with supplementation as needed. OAT or the hybrid OAT (HOAT) has pretty much been standard on and cars and ight trucks for the past ten years or so. It is also the standard for professional truck drivers. It is readily available as well. Just check out the coolant shelf at any truck stop. Finding EG coolant specifically for HD diesel engines, on the other hand, can be a challenge depending on where you are shopping.

The chemistry behind all these coolant choices is mind boggling and mixing incompatible products will result in disaster. It would be advisable to have the work done at a Cummins shop or other reputable and trusted RV or truck service center. Also, know exactly what product is used and have a gallon or two extra on hand. I'm still running the green EG for now, so this isn't an urgent matter until it is time to replace the coolant.

T bogie · 06-03-2017, 08:46 AM

Since I'm going to flush the the radiator and change coolant now would be a good time to change all the radiator hoses as well
I was under the coach doing a oil change and started looking at the hoses not sure I can get to them all especially the one at the top of thr radiator not sure how anyone could change it can't even see one of the clamps
How do you get to that one?
Bogie 2002 FDDS

AKOne · 06-07-2017, 12:44 AM

Interesting thread. Just had coolant flushed and replaced with Fleetguard ES Compleat OAT which has a redish color. Most if not all OAT coolants have the same color and can be mixed with other OAT bands except Shell Rotella ELC. Old Scout, the blue/green is Fleetguard hybrid. Attached is a list of all of Fleedguard's coolants. I went with OAT because I didn't want to mess with test strips, additives, filters and frequent flushing.

RVPioneer · 06-08-2017, 09:41 AM

While OAT coolant will probably outlast most coaches and their owners, it does require annual analysis with a test strip as well as additives when necessary.

T bogie, it is definitely wise to replace the hoses at this time as they are most likely 15 years old. I have not performed the task and will be forking over the "sweaty wad of cash" to have it done when the time comes. Seems that it would be less costly to replace them before they fail rather than after.