Coolant Question

[ROYBUCK]

I have a call into Cummins. But while I am waiting I thought I would run this by the forum members, the coolant in my ISC is 6 years old but it only has about 12000 miles since changed, it has the ES Extended service coolant in it, I just received new test strips the results Freeze point 60% Where the Molybdate and nitrite meets is 4.1, Do I need to change the coolant due to age not miles, even though the test shows positive. Thanks Roy

[wolfe10]

Roy,

From info in your other coolant post today it looks like you will be going with the new generation OAT-based coolant (a good idea IMO).

If so, the new coolant has a 6 year life in normal use-- perhaps longer if low miles.

So, if you are going to keep the coach long enough that you will be changing coolant, I would suggest you do it now. Said another way, the new coolant, used over a longer period of time will be less harmful to the cooling system than the original coolant.

And, as far as testing the original coolant, the primary "out of spec" with older coolant is that it becomes acidic. Did you check the pH?