Changing Coolant - question on Aqua Hot engine preheat and complaint on Beaver

[Mike Shumack]

I'm changing out the coolant (from standard green Ethylene Glycol to CAT ELC) this week. According to the Beaver manual, my coach holds 16 gallons.

I drained the coolant and removed the thermostat (CAT calls it a Regulator). Then refilled with tap water and ran at 900-1000 rpm for about an hour. This got coolant temp up to 125F. Then I drained that, and repeated twice more, until coolant was draining out was clear.

Next I added a gallon of CAT Cooling System Cleaner and tap water and ran the engine for another 90 minutes. Temp is getting to around 125F (since thermostat is removed I can't get coolant as hot - but I know water is fully circulating through the engine and cooling system). I drained that out last night. Tonight I finish up the job.

Today I will run full "distilled water" in the system and then drain that out. Then I will add the final mix of distilled water and ELC.

So my question: I tried heating the coolant with the Aqua Hot Engine Preheat feature. The diesel burner ignites and circulation pump runs but after about 15 minutes or so the burner shuts off. Aqua Hat manual says to "run for about an hour and half". The circulation pump keeps running. Engine temp did not get above 125F. Is this the way it is supposed to work? Outside air temp was in the low 70's. Maybe the Preheat only slightly warms the engine - and is not intended bring coolant temp all the way up to operating temperature (180+F).

Lastly, My Complaint -- The way Beaver installed the coolant surge tank is frustrating, one can not pour any coolant or water (from container or with a funnel). The tank cap is too close to the body - so you have to drop the Surge tank in order to add any fluids. To drop the surge tank you have to remove the air intake tube (so then you cant start engine).
I suppose to just top off the reservoir you could use a hand-held suction pump device, but not very practical for anything over a gallon. Now I feel better. 

[David T. Richelderfer]

I use one of these.

https://www.harborfreight.com/battery-operated-liquid-transfer-pump-63847.html

https://www.harborfreight.com/Multi-Use-Transfer-Pump-63144.html

[Steve Huber Co-Admin]

Mike,
You can also use a length of heater hose and insert a funnel in one end with other in the tank. Slow process but it works. I use same setup to top off Aquahot surge tank.

Be sure to first add a gallon of undilluted ELC before the 50/50 mix. It will mix with the distilled water remaining in your system.

Can't answer your preheat ? as I'm a desert rat.
Steve

[Mike Shumack]

Be sure to first add a gallon of undiluted ELC before the 50/50 mix. It will mix with the distilled water remaining in your system.

I bought the concentrated ELC (not the premix), so I plan to dump in "all 8 gallons of the ELC first", then I'll add the distilled water until the cooling system is full. Once the engine runs it will mix everything together.

As you noted, I don't know how much water is still remaining in the system after draining out as much as I can, but whatever is left in there now is 100% distilled water - so by adding all 8 gallons of ELC first then topping off with more distilled water, I will know I have a 50/50 mix at the end. The total cooling system holds 16 gallons according to Owner's Manual.

Then I will carry a gallon of the 50/50 ELC premix for topping off the surge tank if ever needed.

[Neal E Weinmann]

My experiences with Aqua Hot Engine preheat has it repeatedly heating engine coolant to approximately the 125 degree Fahrenheit mark no matter what the ambient temperature. I believe the manuals phrase the function as heating the coolant “adequately” to support starting the engine. In colder temps, the 125 degree mark has always seemed to indeed be adequate and the engine has started without issue.

[Mike Shumack]

Thanks for clarifying that Neal.
The manual did not specify a temperature - but now that I think more about it -  the coach's hot water (sinks and shower) only get up to about 125F with the Aqua Hot so it makes sense that it would not get any hotter than that in engine preheat mode.

[Michael Peters]

To add coolant I have   a 4' x 1" PVC pipe with 90s on each end. They aren't. glued , just slipon. I can fill both coolant tanks with it. It stores on the rear frame rails, just inside the engine compartment

[Mike Shumack]

BTW - I tried a couple of methods to add coolant to the surge tank (long neck funnel, hose with funnel) but it can not be done. The neck of the surge tank is too high up and the hinged "hood" is in the way to use a funnel. You can see in the photo that when the engine compartment door is open you can't get anything above it (i.e. funnel) and the slots are too small to get a hose through.

The only way is with a hand (or electric) fluid transfer pump, or to unbolt the surge tank and set it on the lower part of the engine opening.

[Jerry Emert]

I use an $8 hand pump from Harbor Freight.  I have one for radiator and one for HydroHot.

[Fred Cook]

Mike, did you disconnect the coolant filter and plug the the lines leading to it? It is no longer needed with CAT ELC.

[Mike Shumack]

Hi Jerry,
I have one of those hand pumps now. This one https://www.amazon.com/Koehler-Enterprises-RA990-Multi-Use-Transfer/dp/B0181EDCZ6/ref=sr_1_5?ie=UTF8&qid=1544707761&sr=8-5&keywords=transfer+pump
I used it when I changed the engine oil and transmission oil, to pump the old oil from oil drain pan back into gallon jugs for disposal. That was just 10 gallons of oil (and my arm looked like Popeye's afterwards).

On this coolant flush/change job, I 'm dealing with 16 gallons (and flushing multiple times). That hand pump would have killed me by now.

But it is a good tool to use "top-off" the surge tank (and add engine oil) as needed. I keep it in one of the storage bays. Thanks.

Tonight I will finish the job. Everything is flushed and I'm adding the ELC coolant in this step and finishing up. So I done complaining about this surge tank setup for now 

[Mike Shumack]

Mike, did you disconnect the coolant filter and plug the the lines leading to it? It is no longer needed with CAT ELC.

Yes. I bought a WIX 24070 (non SCA - filter only) to install in place of the original filter. http://www.wixfilters.com/Lookup/Exactmatch.aspx?PartNo=24070

[Steve Huber Co-Admin]

Mike,
If the C13 filter hose routing is like the C12, you may want to read Gerald's comments in this post before leaving your hoses installed.   http://beaveramb.org/forum/index.php/topic,7755.msg54002.html#msg54002
Steve

[Mike Shumack]

Thanks for pointing that out.

Since the number one cooling system failure by far on a C12 is the hoses that run to the unneeded "coolant filter", I advise everyone with a C12 that is running ELC to remove the hoses to the coolant filter and plug them at the engine. One hose goes to the intake and is visible from below the coach, and the other one enters the timing cover above the water pump and you have to remove the alternator to access it. The fitting in the intake is a 1/2 inch pipe plug and the one under the alternator is a 7/16 hydraulic plug with an O ring seal.

Gerald   

I will add the removal of those lines to my "to do" list.
For now, I'll run the engine with the "unneeded" coolant filter installed - until I find the time to remove the hoses and filter housing.

[Steve Huber Co-Admin]

Mike,
It's easier just to plug the inlet & outlet and leave the hoses and filter in place.
Steve