Replacing Anti Freeze

[Guest terry05dip]

05 Dip ISL 400 rear radiator. Unit seem to be running hot. Have clean radiator numerous times. I shift down and run slower and will still creep upwords of 200-205 on short grades. Now running Fleetguard Extended Service and just found out that instead of using regular DCA I should have been using a DCA4 extended service product?  If this is the case I need to drain and replace. Thinking of going back to regular anti freeze. Can anyone tell me if this is the case and approximately what the capacity is? Thanks to all.

[Romeo84]

Like 200 isn't hot. These motors are made to hit on extreme 220° I've routinely hit 220° pulling 90000 lbs on hills with no issues in my Mach 500 work truck (daycab). Pressurized coolant shouldn't boil over till 240's ish.. imo if I ever get close to 220 I would start laying off of it..I have only had my 2000 signature a year and may totally be wrong but I get the feeling we as owners want to see an issue when there is none. I have done the same.

Run it enjoy it and when she actually breaks down fix it. 

[bklaes]

I have the same coach with the same engine.  Consistently ran at 210, slight upgrade would bring it temp to 215-220.  Warning buzzer came on at 215.  
First exchanged coolant with Zerex ZXPCRU1.  (The capacity is in the Owners Manual)   No difference.
Then bought a gallon of Simple Green and with a garden sprayer.  Doused it from the outside, and opened the floor hatch in the rear closet and soaked it from there.
Waited 15 minutes and thoroughly hosed it off with a garden hose from the inside and out.
It now runs at 181.  Towing a jeep up a hill has never topped 190.
 

Edited October 12, 2020 by bklaes
Added copy

[Pampero]

I will clean the radiator from the outside, use a good degreaser and hose down well. No pressure washer.

You have an AC condenser in front of the radiator, and both need a good flow. AC condenser runs very hot when the AC is on.

[Guest terry05dip]

I have clean radiator probably about every 3000 miles for the last 3 years. Never a change in the temp. Coach has 45,000 on it. 

[Pampero]

The difference on the antifreeze is to prevent bubbles forming on the cylinder sleeves outside walls.

I don't know if will make much difference on the actual engine temperature.

In mine 40 years as an auto technician I saw many sensors that lie. Are you sure that the coach runs at that temperature? I don't know what Cumming does, many cars have two sensors one is a "sender" for your gauge and another for the engine management. A scanner will red both and they should red the same, but with a Diesel I could not tell you more.

I will not be concern with thermostat, usually a faulty thermostat will permanently closed (overheating) or open, longer to warm up.

[Chuck D]

I've attached a Cummins PDF about coolent and coolent compatability. It may help.

Coolent Compatibility.pdf

[Hotrod - R.I.P.]

12 hours ago, terry05dip said:

05 Dip ISL 400 rear radiator. Unit seem to be running hot. Have clean radiator numerous times. I shift down and run slower and will still creep upwords of 200-205 on short grades. Now running Fleetguard Extended Service and just found out that instead of using regular DCA I should have been using a DCA4 extended service product?  If this is the case I need to drain and replace. Thinking of going back to regular anti freeze. Can anyone tell me if this is the case and approximately what the capacity is? Thanks to all.

If you are running green af, it’s important to add dca4 and keep your sca where it’s supposed to be. Cummins has a card to check the chemistry.

Six or seven years ago I switched to zerex zxed1 OAT pink af and with that you don’t have to check sca’s anymore. I added an extender to it at 3 years, zxed3. 

When I change it I think I’ll use That again or  Final Charge which is also Oat and available at Walmart. It’s the af with the truck on the jug. That ought to be good for a decade.  It doesn’t say anything about an extender. The final charge and zerex have drive Cummins spec on the bottle . Make sure you get the one with the Cummins spec. 

These oat coolants are about 16$ a gal for 5050 or 32$ for concentrate which you dilute 5050 with distilled water . I won’t go back to the green stuff which is not extended life. You have to get the oat to not have to do the sca control. There are some extended life coolants that so require sca control.
 

bill g 06 Dynasty

[Bob Nodine]

16 hours ago, terry05dip said:

05 Dip ISL 400 rear radiator. Unit seem to be running hot. Have clean radiator numerous times. I shift down and run slower and will still creep upwords of 200-205 on short grades. Now running Fleetguard Extended Service and just found out that instead of using regular DCA I should have been using a DCA4 extended service product?  If this is the case I need to drain and replace. Thinking of going back to regular anti freeze. Can anyone tell me if this is the case and approximately what the capacity is? Thanks to all.

If you are using the gauge in the dash to determine the temperature I would question the accuracy. If it is actually 205 then no harm done. If it gets to 220 then as others have said you need to back off. I wrestled with this problem for years on our 2006 Diplomat. Cleaned the radiator numerous times and installed new coolant and a new thermostat. Because our oil fill tube had been leaking the radiator and charge air cooler were caked with dirt. Spraying Simple Green in from the bedroom and then using a hose with a wand did not get them clean. I finally pulled the CAC and cleaned it on the driveway and was able to get to the back of the radiator and get all the crud cleaned off. The coach now almost never opens the thermostat which is a 185. We use the Silverleaf to monitor the temperature and oil pressure. 

[birdshill123]

OAT coolants no longer require an extender. Just drain off a few quarts and add new. Shop around  as the concentrate can be found for around $20.

[Hotrod - R.I.P.]

2 hours ago, birdshill123 said:

OAT coolants no longer require an extender. Just drain off a few quarts and add new. Shop around  as the concentrate can be found for around $20.

For the zerex zxed1 product , it specifies the extender be added after 3 years but that is also at way more miles that any of us drive.

I bought a couple bottle of extender, zdex3 for 7$ at zoro.com . Now it’s 17$. My approach is to test the ph to assure it’s above 7.5. The extender ph is about 11 and it brings it up. You don’t want acidic coolant. To my knowledge one would still use the extender with TVs zerex product .  

The final charge product does not list any need for any tuning up.  I’m not sure that it wouldn’t be a good idea to At least monitor the ph over the years. 

Adding a few quarts of concentrate does refresh the chemistry a little. It also increases the percent of af. Be careful not to get that too high . The Zedex3 product is simply a chemistry refresh and doesn’t change the percent af for what that is worth.  

[birdshill123]

Old World Industries makes Final Charge and Peak coolants. They also make various private label coolants including some for Walmart. I could not find the extender so called and spoke with one of their engineers. He was the person that told me to drain some  and add. He also told me to ignore the time limit as in most RV applications we do not drive the miles of an otr vehicle. They discontinued the additive.

[Chuck B 2004 Windsor]

As to the capacity, there are a lot of areas in the engine where antifreeze will collect after draining the antifreeze.  I would also use what is now in the engine to keep from having to flush out the old antifreeze which is very time consuming.  I would add a mixture of water and antifreeze in the bottle as opposed to straight antifreeze.  I would also use what is now in the engine to keep from having to flush out the old antifreeze.  You also might want to consider replacing the thermostat.  Chuck B