Cooling System Maintenance

[rdjl972]

Guys,

We have a 2008 Monaco Camelot 42 foot coach with a Cummins ISL 400 in it. We're full-timers and very pleased with the coach. But we've had the coach over 10 years now and are concerned about the cooling system. I'm inclined to go into Cummins and have them flush out the system, install new rubber hoses and then add coolant & antifreeze. Rather than spend what I think is going to be a pretty penny or more, have any of you guys actually performed this maintenance yourself?

Are there custom hoses involved? How did you replenish the SCA? How much antifreeze do you use?

Any help is appreciated.

Thanks,
Rick

[jacwjames]

What engine do you have. Some have coolant filters that contain the SCA or DCA.

Back in 2015 I had the same concerns on my 2002 Windsor, it was 13 years old. I knew the Crosspoint Cummins manager so contacted him, he gave me a quote to change out the coolant, ~$650. But he recommended I have the coolant tested so I got a kit from JG Lubrication, took a sample and sent it in, the results came back as if the coolant was new so I didn't do anything.

Unfortunately I had road debris take out my radiator later that year so had to have the coolant changed anyway. I questioned whether they should change radiator hoses and he said they would if needed, they ended up not changing any. The Cummins manager recommended the ES Compleat coolant, which is considered a lifetime coolant, although you still have to check the SCA levels.

I just ordered test strips to test. If needed I'll replace my coolant filter with the SCA slow release additive.

[96 Wideglide]

Do it now!

10 yrs, I'd be surprised if there is any SCA left in your coolant, protecting your cylinder sleeves!

Jim, an 07 or 08 ISL engine doesn't have a coolant filter at all, never mind one that slowly releases SCA!

[Happycarz]

They’ve necessary coolant hoses.



What came off

[rdjl972]

Thank you for the guidance.

Harry, what engine do you have? An ISL? Your coach is very close in most ways to mine. Certainly the same Roadmaster chassis, so chances are the hoses are the same too. Were there any "custom" hoses?

Also, did you purchase these hoses at Auto-zone or someplace like that? I also wonder if any of you have tried Monaco National Parts to see if they have any hoses that aren't stock hoses? OR, maybe some surplus places that have Monaco parts?

Also, Jim, where did you get the test strips? At a local Cummins dealer?

Any other help, I'm all ears.

Thank you VERY much for your insight.
Rick

[jacwjames]

I just ordered the test strips off Ebay from a high volume dealer hoping they aren't too old. They do have a shelf life.



To be honest, when I've used them in the past the results are so subjective that I had a hard time telling if the coolant was good or bad, hence the sample to JG Lubrication. I've put so few miles on the coach since having the coolant changed I decided to try and test first.

[Happycarz]

Rick,

Those hoses are all off the shelf hoses.

The two 90° hoses are same part number and available online or at a parts store. The Dayco brand is in the picture, but can be cross referenced to other brands. You will also need two feet of straight 2 1/4” hose to be cut and used where needed.

The 1 1/4” hose should be bought at NAPA. The green stripe, the yellow stripe and blue stripe hoses had high failure rates. Several of us with new coaches were having them crack and leak at 2 years. The NAPA white stripe last 10 plus years. This is the hose goes between the bottom of the surge tank and the Y fitting in the lower hose.

I do have a ISL 400, albeit a 2006 (black engine) in my early 2008 coach. If you have the red engine, you may have other hoses to EGR cooler. Not sure. My engine didn’t come with an EGR.

There is a 3/8” hose that carries coolant to the turbo and is often overlooked.

[veraken]

When I changed my coolant, I used Peak Final Charge

First flush the old antifreeze from your system. Make sure to turn on the dash heat and aqua heat 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, and 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 of Final Charge to fill the rest of the system. Make sure to change your coolant filter to a non SCA filter.

[rdjl972]

I finally had enough time to get under there and look at the hoses I have. I have the black engine too (I think it's a 2007 engine), so guessing that we have the same engine. I too do NOT have an EGR valve, nor do I add DEF when fueling. Very nice and simple.

Question for Harry though; The 3/8" hose that goes up to the turbo, isn't there two of them - one going up and the other coming back? Is it best to access these two hoses from inside the bedroom area of the coach since the turbo is up on the top? How long would the length be if I bought one section of 3/8" hose and cut it in two?

Also, did you have any trouble figuring out when the cooling system is full? OR, did you measure what you put back in so you'd have some idea of when it's full?

Thanks for all your help on this guys. I appreciate it.

Rick

[jacwjames]

I received the test strips last week and checked the expiration date on them today. They are good until next year so they are fresh. Paid $9.95 for 3 test strips off Ebay.

[Happycarz]

Rick,

When I ordered my coach in April 07 I had a choice of the 2006 ISL400 with no DPF, or the ISL425 with DPF. I picked the former.
Interesting that the 06 engine is black and the 2007 ISL425 is red.
Your coach is an early 2008. I would assume.

Buy 10’ of 3/8” fuel line or water line, whichever is easiest to get. At the rear of engine near the thermostat is a T with two 3/8” hoses attached. One goes to turbo and other goes to expansion tank. A third 3/8” hose connects between the top of the radiator and the other nipple in the expansion tank. This turbo coolant drains into the engine and therefore no rubber return hose.

When all the hoses are in place and you are refilling system, look at the metal coolant pipe to left of thermostat. There will be a 1/4” Allen head pipe plug on the top of that pipe to remove and let air out as you fill system. Good luck.

[Happycarz]

Yes, access the turbo coolant hose through the bedroom hatch. You should be able to remove the hatch not in the closet to reach the hose.

[Kamir]

If you have an aquahot, you also have coolant hoses running from the engine to the aquahot. I had one of them rupture on my 2008 Camelot last summer and lost all the antifreeze. Fortunately, this happened in town so I was able to get it fixed without too much hassle. Once this happened, I knew it was time to change all the other hoses so I have a project ahead of me.