Community Forums

CountryB · 11-29-2017, 04:40 AM

I'm going to replace the standard/old coolant in my MH with ELC. I have the ELC and distilled water. I've read it's best to have the engine warm when draining, and then fill with distilled water only, and re-warm the engine for the flush and second drain. The final fill will be 50/50 ELC and distilled water.

After draining as much coolant as I can (from radiator petcock and engine block drain) and refilling with just distilled water to clean out old coolant. Should I use the Aqua-Hot engine preheater feature to warm up the coolant (and help flush out the Aqua-Hot lines) before I drain that and do the final refill?

I'm thinking the engine preheat, which uses a circulating pump to move the coolant, would be useful to flush the 60+ft of Aqua-Hot coolant hose (the lines that run from engine to aqua-Hot and back).

What do you think?

Playtime III · 11-29-2017, 07:02 AM

You will need to flush all of the lines (Aqua Hot pre-heat loop, Dash heater core loop, as well as the block/radiator). So, it wont help; but is necessary.

Be careful with replacing coolant with 50/50 mix. Since you are flushing with water, some water will remain so you will never reach 50/50 balance. Search on here for those (I included) who replaced with concentrate then use 50/50 to top off if necessary.

Expect a challenge getting the thermostat to open and circulate coolant just at a high idle.

CountryB · 11-29-2017, 08:59 AM

Good point on the 50/50 mix regarding straight water still in the system after the flush and refill.

I would expect that the Aqua-Hot engine heater would heat the entire cooling system enough that the thermostat will open once the engine is ruining a few minutes on high idle (or I could remove the thermostat after the first drain then flush with clear water and reinstall it, but that sounds like a lot of extra necessary work).

2 Stroker · 11-29-2017, 11:11 AM

This may help

https://www.youtube.com/watch?v=g6j0ZvjVj8Q&t=130s

2 stroker

CountryB · 11-29-2017, 12:19 PM

Thanks, 2 Stroker. I've seen that video. I actually had a discussion by e-mail with Josh (Adept Ape) on doing the flush on my CAT C13, and suggested he make a video on it.

Although, I did not ask him about the Aqua-Hot question in this post. He said running the engine on fast idle would be enough to heat the engine.

dmurdock · 11-29-2017, 10:11 PM

With the aquahot loop and the dash loop it will be a pain no matter what. You may want to investigate how hard it is to get to the hoses and flush them separately. On mine the dash loop is super easy to get to at the engine..not sure on the aquahot but it's worth a look.

Playtime III · 11-30-2017, 07:13 AM

The dash loop was easiest to drain. The hose is at eye level when the genny is extended. When removed, has plenty of slack to bend it downward and into a container. Just remember to turn up the thermostat/temp on the dash control to open the valve if it was in cooling mode prior.

The Aqua Hot loop is just the engine pre-heat loop and is separate from the other loops that contain boiler fluid. You just need to turn it on so the coolant from the block circulates (and isn't allowed to run empty).

CountryB · 11-30-2017, 07:40 AM

Thanks.
I have a gallon of Cat Cooling System Cleaner (4C-4611) on order. Once that arrives I'll start the coolant change-out project.

veraken · 11-30-2017, 12:10 PM

First flush the old antifreeze from your system. Make sure to turn on the dash heat and aqua hot 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 to fill the rest of the system. Don't forget to change your filter to a Non SCA filter

CountryB · 11-30-2017, 01:16 PM

Quote:

Originally Posted by veraken

First flush the old antifreeze from your system. Make sure to turn on the dash heat and aqua hot 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 to fill the rest of the system. Don't forget to change your filter to a Non SCA filter

Everything you said is what I'm planning to do.
I'm not sure what the "Concentrate Final Charge" is. Is that a cleaner like the Cat Cooling System Cleaner I'm planning to use?

I also have the "AirLift (vacuum filling tool) as mentioned in the Adept Ape video. Hopefully this will help evacuate the coolant that is hard to get out.

https://www.youtube.com/watch?v=-SfhBRvVbtg

Playtime III · 11-30-2017, 02:16 PM

Final Charge is a brand compatible with cummins engines

veraken · 12-01-2017, 04:08 AM

On the Final Charge coolant you can buy it 2 ways. In an undiluted form (concentrate), or in a pre-diluted form (50/50 mix)

Ron Postma · 07-22-2018, 08:24 PM

Here is what I have done. First you need to find from the chassis manufacture the exact capacity of your cooling system, This must include the heater and aqua hot system. Next flush 3 times with tap water running the heater and the aquahot preheat. Do a last flush with distilled water. Now drain as much of the distilled water you can. Add half the capacity of the system with concentrated coolant. Last step fill the rest of the system with distilled water. Run the coach and add distilled water until all air is removed. Doing this you will have an exact 50/50 mix of water and antifreeze.