What Coolant To Use?

[Bonanza]

Hello again my friends, I have a question about Antifreeze/Coolant for my
Cummins Diesel. I would like to add some coolant to my reservoir but don't know what kind I should use. Is it ok to use a 50/50 prediluted coolant like you use in a regular car or light duty truck or do I need something different. Any help on this subject would be appreciated. Thanks

[RVDude]

The quick answer is NO.

You'll need to contact the chassis maker or Monaco and find out what is in there. These big diesels -especially if sleeved - use either an OAT type antifreeze (no SCA/DCA added) or a heavy duty antifreeze with additional (and routinely needs to be tested) chemicals added to it.

These SCA/DCA chemicals (or the OAT type w/o chemicals) prevent bubbles on the outside of the cylinder walls caused by the intense vibrations in a high compression diesel engine. If these bubbles are allowed to exist they will destroy the cylinders.

By all means, do not just fill it up with car anti-freeze w/o knowing the proper antifreeze first.

SCA = Supplemental Coolant Additives
DCA - Diesel Coolant Additives
OAT - Organic Acid Technology

[Bonanza]

Thanks RVDude I was reading in my Monaco manual awhile ago and I think I will call Monaco Monday and find out just to be sure. Manual says 50/50 mixture but does not say what brand and it says ethylene glycol which is what I have, but it states for any car and light duty trucks. Better safe than sorry I suppose.

[buck62]

Quote:

Originally Posted by Bonanza Thanks RVDude I was reading in my Monaco manual awhile ago and I think I will call Monaco Monday and find out just to be sure. Manual says 50/50 mixture but does not say what brand and it says ethylene glycol which is what I have, but it states for any car and light duty trucks. Better safe than sorry I suppose.

It is probably the green ethylene glycol in a 50/50 mix. Need to verify with chassis maker and if it is make sure you check the SCA level using the test strips.

[trouble&rose]

Hey! RV Dude.........not to interupt but where do you get your test strips

[JDT]

Bonanza, don't mean to pry, but do you know if your antifreeze has ever been changed? If not, it is probably past due. I think the recommendation is every 3 years. I changed mine to the red OAT type, Final Charge Global made by Peak. No more test strips and good for 6 years. At 3 years you add some extender, probably less than a quart.

[RVDude]

Quote:

Originally Posted by trouble&rose Hey! RV Dude.........not to interupt but where do you get your test strips

My rig (and genset) runs an OAT coolant, brand name Final Charge.

As stated above, OAT coolants DO NOT use SCA/DCA and must not have SCA/DCA added and must run a blank (empty can) coolant filter. Only an extender is added at 3yr. for a total life of 6yr. Hence I have no need for coolant test strips of any kind.

Final Charge is made by Old World Industries makers of PEAK antifreezes, Sierra Antifreeze, Blu Def exhaust fluid, and even Febreze!

[Bonanza]

Hey there JDT, I am not sure how long it has been since coolant service, we bought our coach a little over a year ago, so I will check the service records and see if I can find out when it was last done. They may have already changed over to the Global Peak Coolant, if not I think that is what I will do. Thanks RVDude and JDT for the info. I bought some 50/50 regular coolant but did not use it, Im not under min in the reservoir tank, just thought I would be safe. We made it home and everything was fine, sure am glad I check on the forum for advice, again thanks guys.

[Batman_777]

Cummins: Fleetguard ES Compleat 50/50

Make sure your SCA (Supplimental Coolant Additive) are OK. It takes a test strip that will show you SCA level.

[hardy1000]

I changed to Fleetguard ES Optimax extended life 50/50.

[walt2137]

Quote:

Originally Posted by trouble&rose Hey! RV Dude.........not to interupt but where do you get your test strips

About any truck supply store

I would call Cummins on the Antifreeze not MONACO or see below and be sure to charge with DCA4, I generally get a case of 6 gal and 6 gal of distilled water from Walmart it is as good and a lot cheaper.

Definition of Heavy-Duty Coolant
A combination of 50/50 water and low silicate antifreeze (ethylene glycol or propylene glycol are acceptable). Protects to -34°F. Freeze protection decreases above 68% antifreeze. Antifreeze must meet ASTM 04985 (GM6038M) specs.
Fully formulated coolant must meet ASTM 06210 (EG) or ASTM 06211 (PG) specs.

[Bonanza]

Thanks walt2137 I will so just that, and thanks to everyone else for your responses.

[RVDude]

Quote:

Originally Posted by walt2137 ...I would call Cummins on the Antifreeze not MONACO...

FYI - It is the chassis maker (NOT the engine maker) that fills the coolant. The exact same engine mounted in different chassis will likely run different coolants. Call the chassis maker.

[SpursMVP]

Quote:

Originally Posted by RVDude FYI - It is the chassis maker (NOT the engine maker) that fills the coolant. The exact same engine mounted in different chassis will likely run different coolants. Call the chassis maker.

I'm going to show my ignorance here....why would Monaco know better than Cummins? I've found more than 5 errors in my HR owners manual in reference part numbers, etc so I'm a bit leery about trusting the company about what anti-freeze to put in the Cummins engine.

To calibrate the oil dipstick...the folks on this forum directed us to the engine manufacturer. I figure the same would apply here.

Anyhow how DO we figure out if our engine uses SCA, etc?