Did some digging about Internationals version of the 6.0(VT365). They are running ELC cat-1 type coolants and here is some comments from a fleet maintenance forum that makes one think that no coolant is safe in a 6.0, and that regular flushing every 3yrs is probably the safest preventive thing you can do besides adding a coolant filter.
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[I have a 2006 CE VT365, 49,000 miles & about to install the 5th EGR cooler. My first question is, what is the actual damage to the cooler? Cracked tube? Pitted tube? Hole burned in tube? The warranty covered all new coolers & now the warranty has ended. Before I can have an opinion to what is causing the damage, I need to know what the exact damage is. I have read a lot of good suggestions for the premature failure.]
[On ours, the little part inside that looks like a radiator starts to leak. Make sure you have all your updates done on that bus. Has it had the ext filter installed. The number of failures on that bus is really bad. We have usually failed 3 or 4 by 150,000 miles. I would perform the test that IH uses to determine oil cooler restriction. Basically run the bus hard for at least 20 min and then (using the laptop) compare the engine oil temp to the coolant temp. If the oil temp is more than like 15 degrees above the coolant temp, you have a restricted oil cooler which is starving the EGR cooler for flow. The oil cooler is plumbed in series before the egr cooler (not the best idea). I am remembering the 15 degree number off the top of my head....it's been a while. Some buses plugged up the oil cooler with material that circulated out of the heater cores. IH replaced them as a part of one of their campaigns (probably expired now). You could have a restristion in this area.]
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Another note, is the Ford gold or hoat coolants were originally designed to work in european cars with high mineral content water. Euro water is much higher in minerals than North America. It is also compatible with green coolants should you need to add some in an emergency situation and that is all you can find. Not that I would use mineralized water in my coolant, but using hose water to flush out your cooling system is not likely to have any adverse effect.
Simple flush method that I used recently:
1) remove radiator drain petcock(19mm) and drivers side engine block drain(8mm allen)
2) let all coolant drain out(into container-s for safe disposal), put petcock and block drain plug back in finger tight
3) refill with hose water through degas bottle, start engine and turn on heater
4) let engine idle for a few min, turn off and drain radiator and block again(into container-s)
5) fill back up again with tap water and leave radiator and block drain plugs barely in place
6) start engine with hose still in degas bottle
7) remove drain plugs and turn hose on, and let what is mostly water now, flow out of radiator and block
8) let engine run like this for at least 10-15 minutes with heater on and the water flowing out of the radiator drain and block drain, the degas bottle will remain full and continue to flow fresh clean water through the cooling system.
9) the t-stat will never open, but really isn't necessary as the water pump is circulating all the water through the block and out the block drain, radiator is consistantly being filled and drained with fresh water also
10) turn off engine and hose and let all water drain out
11) put drain plugs back in finger tight and refill this time with distilled water and run engine again for a few minutes to circulate distilled water
12) drain water again and this time tigten drain plugs up
13) refill with 3.4 gal of your preferred 100% coolant and top off with more distilled water as necessary to the min-level fill line in your degas bottle. This should put you right at the -34F protection level of a 50/50 coolant-water mixture.
My truck is lifted, so this makes it easier for me, but this could also be acomplished on ramps or jack stands, and really can be done within a little over an hour. I used Zerex G-05 gold hoat coolant and this is my second flush in 84k total miles. No signs of any excessive deposits or any silicate drop out, in fact coolant looked real good still, despite being in there for about 50k this time around, first flush was at around 32k. I am not running a coolant filter either and have never used chemicals for flushing. My ect/eot deltas average 7-9 degrees or lower on a long steady drive. Examples: not towing, 6-people and camping gear in truck, ac on, ambient temps 75-80 degrees...ect 184...eot 189-191(t-stat will not open, using just block recirculation cooling, likely due to egr cooler block off) . Towing heavy(4-horses or hay) uphill grade steady at 2200-2500 rpm...t-stat open...ect 197...eot 201.
When I slow down or come to a stop idling, my ect/eot deltas always drop to within 2-3 degrees of each other within minutes and can drop to within 3-4 degrees while cruising steady on flat ground at 60mph.
I know ambient temps play a huge roll in these deltas, the hotter the weather, the higher these averages can be. But I live in a climate zone that rarely sees really warm weather for very long if at all lately.
Harry
