Ok, checked SCA level today and it came out low at 1.4 units per gallon on the grid from the test strip package. I have a 16oz bottle of Fleetgard that says 5 units on it. Do I have to put in one unit per gallon of total capacity? How is that calculated? If so I'd need a lot more than 16oz. Also, is it Ok to just add it to the overflow tank? I don't see any other way to add it. Thanks for any help.

 

I think it runs at 2 units/gal, but I can't find my test strips right now to look at them. The instructions should be on the strip packaging, at least mine was. So I take it since you're asking this question you got a PSD truck.

 

I got a 2001 Excursion. Over the weekend I changed oil with a Motorcraft filter and I used 2 gals of Rotella Synthetic and 6 qts of Rotella T standard. I also tested the SCA's which seemed simple enough at first but there didn't seem to be enough info on the test strips or the bottle to calculate the addition neeeded. Also, it doesn't seem like putting the additive in the expansion tank will circulate it in fast enough.

 

The expansion tank is the only place you can put it. There is no other place to access the system. That tank is under pressure and circulates like the rest of the system.