Just changed the primary filters out. Took maybe five minutes. GLAD I did!!! The drainage looked like 10 wt. dirty motor oil on the newest deuce. The other had some crud but the filter was much more clean.
I am going to change out the secondary filters on the newest deuce , just to be sure. The crud in that primary was really nasty stuff. OK, I edited this because I just changed out the newest deuce secondary filters. The first in line from the primary was kind of messy black, but it moved about with just a finger pressure. The third in line was clean. So, now we all know that having multiple inline filters has a purpose. Just kidding.
Now, I think I have air in the lines and I am looking at how to cure that.
I am really glad that I had enough sense to listen to jatonka, the others that came later in producing spin adapters, it really does make a huge difference. The bad news is if the government had known about the spin on adapters, they deuce would probably still be in service.
It is not only a good idea to put on the spin off filters, but also to change them out from time to time!!!