I used coronan's method below also. I broke the cooler apart in the same place as shown in his post. I thought maybe if the flow was going in a full loop, that I would take the other fitting apart, and would seem like I was getting the fluid from the cooler rather than right out of the transmission. However, when I tried that, fluid came out of the block from the front hose in that coupler, just the same as it comes out of the back fitting in the instructions below. So regardless of where you take it apart, you're going to get fluid coming out of that little block. I put mine back together and used coronan's method since he seemed to describe getting most of the old fluid out.
As someone suggested, I tried the elevated reservoir method, and that still would not pull a suction. I tied a large funnel up to a ladder, attached it with clear hose and clamps to the open hose taken off the back of the block, and filled it up with fresh fluid. Even with that, it would not pull a suction and take the new fluid.
I pumped 6.5 qts out, and as described it starts to cavitate. I put two fresh qts in the dipstick. Pumped out another 3 qts of dirty fluid till it cavitated again. Then put two more fresh quarts in, pumped a little more out. At this point I had about 10 qts of fluid in my graduated bucket.
Started with 10 qts in the transmission, and had put 4 back in so far. I put two more quarts in, them pumped more out until I got that translucent new red fluid in the hose. I went until my bucket read 12 qts before it got clean enough for my satisfaction.
At this point, I put another 8 qts in, ran the car for a bit, and checked the levels once everything got up to temp.
I would up wasting 2 qts of fluid, but at $6.50 each was a small price to pay considering my local Ford dealer wanted $225 for a flush service. I had used a pre-flush treatment, which my local dealer says they also use and they are told by Ford it will not harm the transmission, seals, or lifetime filter. I used a product called Lubegard Transmission Flush that I got from O'Reilly's.
Thanks coronan for the great instructions. I gotta admit I was a little intimidated by this job, but it was pretty easy. Would have gone super fast if I hadn't screwed with trying the other fitting, and with trying the elevated reservoir to see if I could get a suction to take new fluid in at the same spot. Without that trial and error, maybe 1.5 hr job including cleanup. The longest part is screwing with the snaps that hold the fender well in in addition to the 5.5mm screws.
