Reading different threads I realize that I may have used different brands (Mixed). I think I used what appeared to be compatable but now I am concerned. So I want to change all of my coolant and do a couple of the hoses while it is drained. So what would be recomended as to the procedure and coolant type to use? I think I want to change the Aqua Hot coolant at the same time. Also are there drop off places to dispose of the old coolant?
Thank's Phil
Phil,
Below is from an old article I wrote on changing coolant. As far as replacment coolant, I would recommend one of the OAT coolants. Caterpillar ELC, Fleetguard OAT, Shell Rotella (which was OE in many Foretravels), etc. They are the "maintenance free" alternatives to the older generation "low silicate for diesel coolant with SCA" coolants.
For disposal, check with your city vehicle maintenance department. I have found them helpful in either taking it or recommending an alternate.
Cooling System 101
I just changed out my coolant and replaced all water hoses and belts. Thought I would share the experience.
To my knowledge all RV manufacturers use a "low silicate coolant for diesels" with included or added SCA. Coolant needs to be changed per manufacturer's instructions (usually every 3 years). Additionally the SCA, pH and freeze point need to be checked on regular intervals using SCA test strips and SCA added as needed. The test strips are inexpensive and easy to use. When either the time lapses (time starts when coolant is installed in cooling system, NOT when purchased) or testing reveals an out-of-line conditions like pH or freeze point, it is time to change it. You can avoid all the testing and SCA adding, and go to 6 year change intervals by going to an Extended Life Coolant and get better cooling system protection as well. Whichever coolant you choose, most of the steps are the same. The job is reasonably time consuming TO DO RIGHT, but low-tech.
First step is to determine your total cooling system capacity. Your chassis maker or coach maker, not your engine manufacturer is the proper source. Then buy enough coolant (concentrate, not pre-dilute) to make up 50% of that volume. If going back with a coolant that requires additional SCA, purchase that as well. Also purchase 1.5 times system capacity of distilled water for a final flush plus final fill (50%). Also a good idea to change the engine thermostat and thermostat gasket as these are a wearing component and it involves very little more work while you are there. I know Caterpillar recommends thermostat (they call them regulators) every 3 years.
Turn dash heater to full hot for the rest of the procedure—fan off. With the engine cold or at least cool, drain coolant. On some, there is a drain cock. On others, pull the lower radiator hose. Two Rubbermade 10 gallon storage bin lined with black trash sacks so they don't get dirty work well. At the end of the whole process, use a coffee can and funnel to pour old coolant into new coolant/water containers for recycling. Our city maintenance shop recycles coolant for free.
Refill cooling system with tap water. IMPORTANT: Be sure to remove any air lock from the thermostat housing. Some systems have a hose set up for this—on ours I just loosen the coolant line to the air pump and bleed the air out. Allow engine to warm up (using the cruise control to select idle speed of 1,000-1,100 speeds this up). Run for about 10 minutes at regular temp. If the temp gauge does not rise as normal, you likely have an air block and need to bleed the thermostat housing. Allow engine to cool 20-30 minutes and drain again. Repeat until the effluent color is clear.
At this point, if this is the first coolant change on a 2-3 year old coach and you are not changing coolant brands/types, skip right to "Last rinse". For older systems or when switching types of coolant, add a Cooling System Cleaner. Follow the directions. Run, allow engine to cool, drain and again flush until effluent is clear. The flushing is markedly sped up by pulling off the heater hose (usually 5/8" to ¾" lines) going to dash heater/motor-aid water heater, etc from the water pump. Put a hose nozzle in the hose and let it run until it comes out clear. Run the engine to temperature at least once with tap water.
If your hoses are over 3-4 years old, this is a good time to change them as well (before last rinse). Same for thermostat(s).
Last Rinse is with distilled water. At $.62/gal at Walmart, it is silly to skip this step and leave your system full of high-mineral content water (there will be several gallons of residual water that you can not easily remove). Run engine for 10 minutes after getting to operating temperature. Cool and drain. Also drain and flush your coolant overflow container and refill with new coolant/distilled water.
Add the proper amount of Coolant CONCENTRATE (NOT PRE-DILUTE) to make 50% of cooling system capacity. So for a cooling system with 20 gallons capacity, add 10 gallons of Coolant CONCENTRATE (plus 1/2 overflow container capacity). Top off with distilled water to achieve your 50/50 mixture—it doesn't matter if you only have to add 1 gallon or 10 of distilled water, you KNOW you have the proper 50/50 mixture.
This is also a good time to clean the OUTSIDE of the radiator/after-cooler whether you have rear or side radiator. On rear radiator, most if the debris will be on the FRONT of the after-cooler (accessed from under the bed). On side radiators, most debris is on the outside of the after-cooler (side of coach). If it is just dirt, a hose and regular nozzle is all you need. If greasy or oily, use Joy liquid (dish washing detergent) in a spray bottle. Be SURE to rinse it off completely. You need to insure that the perimeter is as clean as the center. Ya, I know it is easier to see the center, but the fan blades "sling" the dirt to the perimeter.
Check belts while you are in there.
Thanks Brett That nailed it! I will use this as my guide.
Brett
What about " Evans waterless coolant".
Do you know anyone who converted to it and installed a higher temperature thermostat?
There seems to be a lot of praise for the product but I did also find negative comments from the supplier of a competitor product.
My SCA's are at the max level, however after they drop I wil install Extended service or waterless coolant.
Wyatt,
No, I have no experience with Evans waterless coolant.
I just run 50/50 distilled water and Caterpillar ELC. If I had a Cummins, would probably use the comparable Fleetguard OAT-based product or Shell Rotella which later model Foretravels came with from the factory.
I have seen nothing from Cat or Cummins discussing Evans as an alternative. Both manufacturers have basically the same coolant recommendations-- either traditional "low silicate for diesel with SCA (DCA) that needs to be checked and added OR the OAT-based and basically "maintenance free" coolants.