I'm coming up on the change coolant interval for my 400 ISL (early '06 coach) and confused on what my options are. My ISL currently has the green coolant (ATSM 4985) which I believe is the standard Cummins EG and requires periodic hecking/adjusting of SCA levels. If I opt to move to one of the other formulations will I need to completely flush the existing antifreeze in order to make the change or is there a conversion procedure for the existing antifreeze (assuming current antifreeze is ok)? I know there is another thread on the subject but I did not understand some of the banter and was left somewhat confused. I would like to get away from managing SCA levels and increased coolant life.

I went from green to red coolant (Final Charge) in January, this year. If you want the simple solution, call Old World Industries (the manufacturer of Final Charge). Their contact number is 800-323-8755. I found them to be very friendly and helpful.

When I made the switch, there was no short cut to the complete flush mentioned in your post.

Gary,
I was afraid a complete flush would be required. I'll give Old World a call. Looks like a lot of folks are happy with their Final Charge product bansed on another thread.

mark

Sixpack98,
Although this doesn't directly answer your question I hope you will find the following information useful.
I'm about to change the coolant in our 04 Cummins ISC330. I'm switching over from the green coolant to the red OAT(Organic Acid Technology) coolant myself because I like the idea that the OAT coolant is easier on the metals and I will no longer have to add the SCA and do periodic checks.
I ordered the ES optimax from fleetguard only to find the price they quoted me per gallon was 13.70 a gallon instead of 7.80. Big difference to me since I need 9.75 gallons of the stuff plus I'm going to do the generator also.
I instead read all the Coolant information on Cummins Quickserve sight and how the other coolants must meet the Cummins requirement 14603. I decided on the Final Charge Global(OAT) coolant. It meets all the requirements and its 9.94 a gallon at Wal Mart. I actually cleaned the shelves out at two Walmarts to get what I needed but hey I figure they will see its selling and stock more.
Also I don't know about your manual but mine recommends a flush when changeing out coolant and in doing so it recommends using a sodium carbonate mixture of 1 lb. to 6 gallons of water and poured into the coolant system after the intial drain and flush. Don't confuse sodium carbonate and sodium bicarbonate.
Had to look up sodium carbonate but basically its a (soda ash) or sodium salt of carbonic acid used for multiple purposes. One of them is as a ph balancer in pools. I looked in the pool section and sure enough it comes in various size containers listed as pH +. The ingredients panel says its 98 % sodium carbonate and 2 % inert materials. You pour ths mixture in and then run your engine up above 176 degrees for five minutes then allow it to cool and drain. Refill with fresh clean water and bring engine up to temp again. Flush again until water is clear. Sounds pretty straight forward but I will let you know when I do it next week. Of course you could pay someone to do the maintenance but what fun would that be.
Good Luck to you on your changeover.
Letsgoagain

If you are changing from Green coolant to OAT you need to check the low coolant sensor. If it is a two-wire sensor it needs to be replaced because the old sensor will give false readings. That is what Spartan told me. They also said the ECM will need to be reprogrammed.

Letsgoagain,
Thanks millions for the procedure and where to find the coolant and flush. I'll probably do the changeover at the end of the season. Ought to be a lot of fun getting rid of that much coolant. BTW, what does the sodium carbonate do?

Norm,
My MH has a 2 wire sensor so I should be ok. Probably should check with Monaco/Cummins though.

mark

Sixpack98,
The sodium carbonate is used as a agent to help clean the old coolant,sca and other buildups in the system out. Just how it actually does it and how effective remains to be seen. All I know is thats what my owners manual says to do so I'm going to give it a whirl.
By the way. I glanced at the coolant tank today and I'm not really seeing any wires that detect the levels. Do you know if they are attached on the underneath or perhaps back side out of sight? Has me a little concerned about the number of wire thing and if I need to modify the wiring.
I'm probably going to perform the coolant changeout this coming weekend so I'm trying to get all my stuff lined up. Probably give Wal Mart a call and ask if they will take the old coolant and I've already purchased a new thermostat that will get changed out when I do the procedure.
Letsgoagain

Letsgoagain,
I think the coolant sensors are on the bottom or back of the overflow tank but have not really looked at them. I looked at the wiring schmatic ('06 Endeavor/Diplomat) and the coolant level sensor is 2 wire so I think we are ok. I would be really surprised if were 3 wire. I might give Monaco a call though, better safe than sorrry. Also want to ask them if any programming is needed for the Cummins. ]

I searched on sodium carbonate and its use in cooling system. I'm not a chemist but what I understand it does is it exchanges ions with the scale that builds up in the cooling system. This causes the scale to sluff off from the walls of the cooling system (and radiator I guess). Not big flakes cause this is at the molecular level. After the ion exchange the sodium carbonate changes to sodium bicarbonate which neutralizes acids in the cooling system. Sounds like a good thing to do unless you have a fouled cooling system which would require some other procedure.
Let me know if Walmart will take the old antifreeze. They might charge you a disposal fee but I doubt it would be much. How difficult does it look to change out the thermostat? I'm genreally pretty handy but there is always a dark cloud that follows me around and seemingly easy jobs turn out to be a nightmare. LOL

Again, thanks for helping me through the antifreeze confusion I was having.

mark

Sixpack98,
I just talked to a Monaco tech about any issues switching over to the new coolant. I specifically asked him if there would be problems with the sensors in the coolant tank detecting the correct level of coolant and if there would be any programming needed. I mentioned that there were other manufacturer's reportedly having some issues with a three wire sensor system on the coolant tank. His reply was that he had never heard of any problems and this was the first time he had even heard of the possibility of a problem switching over.
Needless to say this leaves me feeling somewhat uneasy about his lack of knowledge and the possibility that I might have problems during the switchover. I'm hoping that I'm not going to be the first to experience problems.
Regarding the thermostat changeout difficulty. I can't say yet because I haven't crawled underneath to see exactly where its at.
As I mentioned I'm going to do the changeover this week end so I will let you know how it goes.
By the way thanks for the explanation on how the sodium carbonate works. I did call a pool place and they have the sodium carbonate that is 100% sodium carbonate. If you remember I said I bought some at Wal Mart and it was 98 % sodium carbonate and 2 % inert materials. Don't know if it matters but I will be returning that to Wal Mart and going with the 100% stuff.
Update - Here's a little more info. I just went out and crawled around underneath and found out two things. First is that I have a two wire sensor on the coolant tank so I shouldn't have any false level indications. The other thing is I believe I found out where the thermostat is located. Followed the radiator hoses and the one I need I'm pretty sure is located on the top back of the engine. I can access it by taking the engine access hatch out in the closet. Should be easy enough to work on from there.
Letsgoagain

This message has been edited. Last edited by: Letsgoagain,

Letsgoagain,
No surprise about Monaco Tech. I'll post a message to Bill Duckwitz, the resident guru on the Monacoers yahoo group. He will know the number of wires on the coolant tank and if reprogramming is required. Also, I saw parts diagram and I believe the thermostat housing is on top of the engine, curb side adjacent to the valve cover. I looked at some pictures I took of the top of my engine (I need to get a life) and it looks like a very simple procedure to replace the thermostat.

Mark,
Looks like I was editing my last post with further info while you were typing your reply.
I think the thermostat housing is perhaps on the road side on my engine but maybe thats the diffence between your ISL and my ISC.
Thanks for all the good information.
Keith

Good evening,
Did the coolant changeover to the organic acid technology(Red Final charge) and thermostat changeout this week end.
Took a alot longer then I thought to do this but thought I would post so it will help some of you comtemplating this procedure.
The biggest thing is took more flushes then what the book says to get the old coolant out. At least it did for me to feel comfortable that it was cleaned out. I probably overdid it but wanted to be sure.
I initally drained all the old coolant out then flushed with water till clear. I then filled with water and drove the motorhome to get the coolant up to temp so the thermostat would open. Ran the heater while driving so water was flushing through the hose that goes to the front heater. I then drained that water out and flushed a while with water. 2nd fill was with the sodium carbonate water mixture and then drove again following the same procedure and came back and flushed.
3rd fill was with clear water, drive again and then flush again.
After the first fill I waited till the engine coolant cooled until it was below 120 degrees. This took about 2 hours of waiting. I found out through trial and error that you don't have to wait that long. I just waited about 15 minutes on the second drain,opened up the drain and let it drain a bit then opened the radiator cap. Same on the third and it worked out fine.
The thermostat changeout was a little tricky. I accessed the thermostat housing by taking the engine access hatch off in the bedroom closet. On my engine I was looking right down on top of it. I had to take two nuts off of a clamp that was welded to a bracket that holds the water outlet pipe that conncects to a hose that connects to the thermostat housing. This gave me the flexibility to loosen and remove the upper end of the hose that connects to that pipe which in turn gave me more room to loosen the thermostat housing bolts. There are two bolts to remove and they are 10 millimeter in size.
The housing lifted right off. There isn't a gasket to worry about. There are two o-rings that fit on the thermostat itself and that is what seals and prevents liquid loss.
Took me all day starting around 10:00 a.m on Sunday working until around 6:00 p.m and then about 4 hours this morning to finish everything.
I drove the motorhome to have the front end tires aligned and had the silverleaf on to monitor the coolant temps and everything works right and I don't have any leaks.
In the end it was a long job but learned some things a long the way and the best part is I'm switched over to the OAT coolant and won't have to monitor or add the SCA's anymore.
I have a feeling that if I had paid someone to do this that they would have drained the old coolant, flushed it once and refilled with new coolant. I wasn't very comfortable with that idea so I did it myself and saved myslef several hundred dollars to boot.
Long post I know but hope it helps someone.
Letsgoagain

Letsgoagain, I have the 330 in my 05 Ambassador. Is the thermostat a special one from Cummins?

Thanks for your post. I'm getting ready to do this so I made a copy for future reference.

Jim

JDT,
I don't know if the thermostat's would be different between your engine year and mine.
I did purchase mine from Cummins.

The part number for the thermostat is 3940632.
The part number for the two O-rings is 145581.
Nothing special about it that I know.
Letsgoagain

Letsgoagain, I hope you see this today. We are leaving on a 2K mile trip Saturday and I decided I might do this tomorrow. I called Final Charge and the guy recommended using the concentrated form because if there is any residual water left in the system after flushing then you have less than a 50/50 mix. The problem is the only place I could find the concentrate is a 120 mile round trip away. Our local Wal-Mart has 10 gallons of the pre-mixed stuff.

My system requires 9.75 gallons, probably the same as yours. Were you able to get all the required amount in and was there anything special you did to make sure you got all the flush water out?

Also, I called Cummins to make sure I had the right part number for the thermostat. The guy asked my why I was changing it and I told him it was in my Monaco owners manual. He said Cummins has no requirement to change it, just the anti-freeze at 2 years. I will do it anyway, mainly because I'm almost 2 years late in the change.

Jim