Coolant/Antifreeze

Jon,

This thread has about seen its day, however I think that it raised awareness of the importance of maintaining ones cooling system. I have my doubts whether or not the coolant needs be changed at regular intervals, say two years, or longer with the extended life coolant. I think it is common knowledge that Glycol does not wear out, what wears out are the additives to protect the engine, the organic compounds have a slower "burn" rate than the inorganic. I did a fair amount of research on this topic, and while I certainly claim to be no expert, it is apparent that if the proper ratio of SCA's are maintained, the coolant is still good. Looks to me like the additives in extended life coolant cannot be replaced by adding additional organic things...maybe they make it but it is certainly not marketed openly. I am positive that when adding additional SCA's cannot bring the fluid into tolerances, it is time for a change. The use of automotive antifreeze is probably not wise, however if it meets the 4985 spec, it looks to me like it is certainly ok in a pinch, provided that one adds the SCA's. My best guess is that there is a point where additional SCA's do not work, the coolant as we know it, is worn out and time for a change; that may well be two years or five years and in rare cases ten years!

John

At the United Engine seminar I asked about the life recommendations for Transynd. They list 4 years and XXXX miles if the coach does not have a retarder, or 4 years and 1/2 XXXX miles if it does. The presumption is heat is the enemy because with the retarder we can bump up against the 300 degree limit. So my question was if we keep temps to a max of 230 instead of allowing them to hit 300, even if wehave a retarder, can we observe the greater limit?

The response was that when the engineers specify a limit for the life of fluids they pick in his words "a one size fits all" value. I suspect the coolant life limits are similar. As long as certain values are maintained it is likely for our average usage which is likely 10% or less than the commercial usage we can probably extend the intervals.

Having said that however, I suspect strongly (but have no proof) that the 2 cycle engines are hard on coolant and silcone dropout and the resultant plugged radiator cores was proof there was a reason for the suggested intervals. Despite adherance to the coolant maintenance schedule with my first coach the radiator had to be recored after 10 years. I don't think the series 60 is as sensitive. But the thing that keep me following the schedule is the chemistry that protects the nitriding of the cylinder liners, the failure of which will create erosion and cratering on the back of the cylinders due to the vibrations imposed on them by the combustion cycle.

What we need is a large truck fleet owner to become a POG member and to educate uson what is really important for owners to maintain.

A friend of mine owns Swift but he's kind of a weenie and doesn't play well with others...... BTW he doesn't like Detroit, they wear out too fast...he's a caterpillar guy ....no doubt because of EC-1.

John

So, in a nutshell, if you change out coolant and filter every 2 years (and use those pesky test strips in between), you're basically going to be OK?

I really don't want to become a chemist at this stage of retirement, it's hard enough to try to be an electrician/engineer/carpenter/pipefitter/mechanic/bus driver :)

Quote:

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So, in a nutshell, if you change out coolant and filter every 2 years (and use those pesky test strips in between), you're basically going to be OK?

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Yep. Although if you read the DD manual I posted, it did say 300,000 miles or 2 years, whichever comes first! So, for you large mileage guys ..... :eek:

Well, I am getting ready to change my antifreeze. It has been about two years since the last change. I have read and reread the posts on this thread and I am a little more confused than when I started.

I had made the decision to use Fleet Guard Extended life, because it is on the list of approved DD coolants. It is an OAT coolant. Then I notice that Ray's friend at DD said don't use an OAT coolant. I called several truck shops this morning, and got everything from, "any antifreeze is okay, just use Prestone" to use "Fleet Guard" in DD engines.

The one thing I've noticed is that each shop has a strong tendency to push whatever they have on the shelf at the time. I got different recommendations from 4 different shops this morning. Unless someone can really explain to me me why I shouldn't, I plan to use 100% Fleet Guard and mix with distilled water. I am going to try to drain everything possible from the bus and intend to raise the front of the bus somewhat to hopefully drain more out the rear. Speak now or forever hold your peace!

Dale, from Brian's post #27 of this thread:

"7. Caterpillar developed and markets EC-1. They also developed a test strip and lab analysis system which EC-1 users can avail themselves to: http://www.cat.com/cda/files/87058/7/elcfaq.pdf
8. The use of a premix coolant eliminates water quality concerns."


This EC-1 is the only product I will use until something better comes along.

Go to Caterpillar to buy it, they will not try to sell you anything else.


JIM

Dale,
I was advised by W. W. Williams Detroit Diesel to NOT use the extended life anti-freeze. Their reason was that is is next to imposable to drain the system in its entirety so there will be a mixture of regular and extended life anti-freeze mixed together. The new mixture will be a compromised extended life mixture and could cause damage in the future. They said drain every two years and play it safe.

Denny is correct, but Williams is hardly unbiased.

The correct answer is either stick with the DD coolant and maintain it as necessary, or opt to go with the EC-1. If the choice is EC-1 then it is not a simple drain and fill. The system either needs to be completely drained which is somewhat labor intensive and varies with each converter and how the coach has been set up, or the system needs to be emptied, refilled with fresh water and circulated, then drained, then refilled with fresh water, circulated, then drained, etc until the old coolant is less than 20%. The 20% number comes from the manufacturers of EC-1. I think if I were to do it (I will be doing it in August) I would flush the system sufficiently to get the remaining old coolant down to less than 5%.

Changing coolant is expensive and a real pain. I am opting to use EC-1 just so I don't have to deal with the coolant change every two years.

But, for anyone contemplating EC-1 there are some critical issues to understand. Denny has the most critical thing correct. Every effort should be made to get as much of the old coolant out as possible. The second thing is to replace the coolant conditioners with dummy cartridges. You do not want to add SCAs to EC-1 coolant. EVER! The final thing to recognize is that EC-1 has a life of 600,000 miles or 6 years. We likely will not hit the mileage limit, but we will hit the 6 year limit. EC-1 is not permanent.

Good catch Denny.

Jon,

On a Country Coach, in order to completely remove all coolant, one has to remove the plastic shield.......truth hertz...