Dynasty coolant flush or drain and replace?

[pduggs]

Attached is my coolant analysis for 2008 Dynasty 425 ISL. I confirmed from prior owner that coolant is original. My question is should I do a complete flush or merely drain and replace?

I spoke with Cummins Ocala who told me a flush is not necessary, if I am not experiencing any overheating problems. He told me he can get most of the coolant drained out at the radiator, then will replace with new coolant. He thinks this is all that is needed.

Any thoughts?

[distaff]

You really only need a flush if you are changing coolant types. I went to the extended life coolant and had to do a flush. If you don't, the extended life coolant won't have the extended life you wanted.

If there is evidence of contamination or significant sludge a flush would also be a good thing.

[96 Wideglide]

1.3 SCA is very low. Wonder if he ever added any.

I hope your cylinder liners aren't pitted.

[walt2137]

I think i would do a flush and the reason is Monaco usually used the old type green HD coolant and he is not sure what type is in the engine , test sheet states it is yellow. I would definitely do a flush and be sure to leave the dash heater in the heat on position to drain it also when you flush.

[distaff]

Again, if you are staying with the same type of coolant, and you intend to monitor and add the additives, you don't need to flush, just drain and refill.

I would consider changing out to the ELC type that doesn't require additives, but that requires a flush and if you have it done will cost a couple of hundred bucks.

If you do go ahead and do a flush, without doubt changed to the long life (ELC) coolant.

[vsheetz]

Flush and extended life coolant, IMHO.

[BigLar368]

I just went through this with our RV. I never had the old coolant tested but knew it had to come out as I wanted the extended life coolant (OAT). I used both Cummins flushes and it took about 2 days to do it correctly or at least the way I wanted to. My old coolant looked clean but that flush told me otherwise. Lots of contaminants came out. In my opinion if you plan on changing coolants go ahead and do a flush with the Cummins products and then which ever extended life coolant you choose. There are several write ups floating around here of members who have done the flush themselves. Good luck.

[veraken]

If you are going to change your coolant you might as well flush it and change over to the extended life coolant.

First flush the old antifreeze from your system. Make sure to turn on the dash heat and aquahot to enable the old coolant in the heater hoses to be circulated out. This may take 2-3 cycles and for this I used regular tap water. For the final flush, I used distilled water. I bought 2 gallons of the Concentrate Final Charge, after the flushing was good, I added the concentrate (2 Gallons) to the system, as there is always some water left behind in the system after draining. Then I added the 50/50 mixture to fill the rest of the system.

[vito.a]

I just purchased 13 gallons of Cummins Fleetguard Compleat OAT extended life concentrate coolant and a gallon of Cummins Restore plus.
I plan on draining the old coolant and then flushing it using the Restore Plus and then adding the new OAT coolant (with lots of tap water then distilled water flushes in between).
I also purchased a new thermostat and will pull the old thermostat for the flush and then install the new thermostat just before adding the new coolant.
I'm going to try to do it myself as I just don't think you will find a shop that will spend the time doing it correctly.

After this, my cooling system should be good for the life of the coach.

[pduggs]

After speaking with a number of experts, I don't need to flush and replace my coolant. All I need do is drain off an amount determined by a mathematical equation JB Lubricants was kind enough to provide, then add distilled water to get the dilution rate back to 50-50.

My coolant is in excellent condition, but the percentage of antifreeze to water is incorrect at 65/35.

Thanks to Tom at JB Lubricant and Cummins Tech Support for clearing this up for me. Unfortunately, Alliance Coach and Cummins Ocala were of little help in this matter.

[BigLar368]

Originally Posted by vito.a

I just purchased 13 gallons of Cummins Fleetguard Compleat OAT extended life concentrate coolant and a gallon of Cummins Restore plus.
I plan on draining the old coolant and then flushing it using the Restore Plus and then adding the new OAT coolant (with lots of tap water then distilled water flushes in between).
I also purchased a new thermostat and will pull the old thermostat for the flush and then install the new thermostat just before adding the new coolant.
I'm going to try to do it myself as I just don't think you will find a shop that will spend the time doing it correctly.

After this, my cooling system should be good for the life of the coach.

Vito, I guess me and you think alike. I don't think any shop would spend a third of the time it took me to do mine but I do most everything myself. When I did mine I did both of the Cummins flush and I glad I did. There was some scale but I did not see any rust. After I drained the second flush I was astonished how much rusty water came out. I did think about removing the thermostat prior to the flush but I did not figure it would ever get hot enough so I left it in. It was pretty scaled up too and when I removed it after the final flush I could see where the flush had cleaned it. Also my manual says 9.75 gallons total capacity. Don't believe that. Mine was at least 12 gallons. One more thing....I took the original petcock off cause it would have taken forever to drain and just installed a 1/4" pipe plug. I could zip it off fairly quick in between flushes with my impact driver and never get wet.

[Spk64]

Originally Posted by vito.a

I just purchased 13 gallons of Cummins Fleetguard Compleat OAT extended life concentrate coolant and a gallon of Cummins Restore plus.
I plan on draining the old coolant and then flushing it using the Restore Plus and then adding the new OAT coolant (with lots of tap water then distilled water flushes in between).
I also purchased a new thermostat and will pull the old thermostat for the flush and then install the new thermostat just before adding the new coolant.
I'm going to try to do it myself as I just don't think you will find a shop that will spend the time doing it correctly.

After this, my cooling system should be good for the life of the coach.

I did the this myself 2 years ago. I think it ended up being about 11 flushes in total. Once it was running clean with tap water I added the Restore. I was amazed at how much gunk came out after using it.
Process for me was as follows
Drain Old
Add tap water
Bring up to temp (with front heater on)
Cool and drain
Repeat till clear
Add Restore
Bring up to temp
Drain and repeat with Tap water till clear
Drain and add Distilled water
bring to temp
Cool and drain
Repeat 1 time
Add full amount concentrate coolant required for full capacity at 50/50
Top off with distilled

It was a long process over a few days as I was in no hurry.

First and second draining of system was taken to drop off location. After that it was pretty much water, so no need to capture it.

[pduggs]

Originally Posted by vito.a

I just purchased 13 gallons of Cummins Fleetguard Compleat OAT extended life concentrate coolant and a gallon of Cummins Restore plus.
I plan on draining the old coolant and then flushing it using the Restore Plus and then adding the new OAT coolant (with lots of tap water then distilled water flushes in between).
I also purchased a new thermostat and will pull the old thermostat for the flush and then install the new thermostat just before adding the new coolant.
I'm going to try to do it myself as I just don't think you will find a shop that will spend the time doing it correctly.

After this, my cooling system should be good for the life of the coach.

Originally Posted by BigLar368

Vito, I guess me and you think alike. I don't think any shop would spend a third of the time it took me to do mine but I do most everything myself. When I did mine I did both of the Cummins flush and I glad I did. There was some scale but I did not see any rust. After I drained the second flush I was astonished how much rusty water came out. I did think about removing the thermostat prior to the flush but I did not figure it would ever get hot enough so I left it in. It was pretty scaled up too and when I removed it after the final flush I could see where the flush had cleaned it. Also my manual says 9.75 gallons total capacity. Don't believe that. Mine was at least 12 gallons. One more thing....I took the original petcock off cause it would have taken forever to drain and just installed a 1/4" pipe plug. I could zip it off fairly quick in between flushes with my impact driver and never get wet.

Originally Posted by Spk64

I did the this myself 2 years ago. I think it ended up being about 11 flushes in total. Once it was running clean with tap water I added the Restore. I was amazed at how much gunk came out after using it.
Process for me was as follows
Drain Old
Add tap water
Bring up to temp (with front heater on)
Cool and drain
Repeat till clear
Add Restore
Bring up to temp
Drain and repeat with Tap water till clear
Drain and add Distilled water
bring to temp
Cool and drain
Repeat 1 time
Add full amount concentrate coolant required for full capacity at 50/50
Top off with distilled

It was a long process over a few days as I was in no hurry.

First and second draining of system was taken to drop off location. After that it was pretty much water, so no need to capture it.

Hi All, I am curious why all of you chose to flush and replace. Did you have the coolant analyzed showing it in poor condition? Or, did engine temperature increase or overheat? Or, was it another reason?

I like the idea of flushing the system to get it good and clean, but my coolant analysis shows it in excellent condition, even though it is 11 years old. I have not experienced any overheating issues or increased engine temperatures, but it is the OEM coolant.

As coolant ages, does it lose it's effectiveness? If so, would this not result in increased engine temperatures and a coolant analysis revealing problems?

[BigLar368]

Originally Posted by pduggs

Hi All, I am curious why all of you chose to flush and replace. Did you have the coolant analyzed showing it in poor condition? Or, did engine temperature increase or overheat? Or, was it another reason?

I like the idea of flushing the system to get it good and clean, but my coolant analysis shows it in excellent condition, even though it is 11 years old. I have not experienced any overheating issues or increased engine temperatures, but it is the OEM coolant.

As coolant ages, does it lose it's effectiveness? If so, would this not result in increased engine temperatures and a coolant analysis revealing problems?

I believe I am the third owner of this RV. I noticed one day most of the metal coolant pipes were very rusty and I had an unknown green coolant that who knows how old it was. That is why I went ahead and flushed mine so I would know exactly what I have. After a ton of reading online and talking to others I chose the OAT coolant. I wont have to worry about it for another 4 years.