I am making a trans fluid flush machine. I want to connect a vacuum source to the fluid line coming from the transmission to the cooler. Is it the line going to the top or the bottom of the cooler?

 

It will not do you any good. These transmissions have internal thermostats that do not open until the fluid temp reaches 200*f. Its not easy to get the fluid that hot without pulling a trailer up a mountain in the summer time.

Your best bet is to simply pull the pan and replace the filter and however much fluid that the pan holds at regular intervals.

 

I make an equipment that uses vacuum to pull/vacuum the fluid thru the thermostat.
It's worked on every vehicle I've tried so far. If they had a dipstick I could do the service thru there, but no dipstick.

 

http://edidist-public.sharepoint.com...%20Rev%201.pdf

You'll damage the transmission. There are few transmissions with internal thermostats, but the 6R80 just happens to be one of them. There are specific procedures to get the fluid changed by companies that make fluid exchange machines. You don't even know enough to realize it has a dipstick. You're asking for trouble.

 

It has a hidden dipstick?

 

I believe it has a short one by the actual transmission. On the side and you have to access underneath the truck

 

This is good advice.... The Transmission has several solenoids that leave particles in the fluid/filter. The Pan needs to be dropped and the Filter changed as well as the fluid every 30,000 miles.

The Passenger side of the Transmission has a metal plug that has to be removed to access the Dipstick, which is approximately 3 inches long and screws into the transmission.

 

Says who? Not Ford.......

 

rofl. don't forget to regularly change the blinker fluid filter as well and flush the exhaust system.... has to be done every 2k miles.

Ford recommends this @ 150,000 miles:

"Change automatic transmission/transaxle fluid and filter"

at 150,000 miles (!) ....

 

Fluid may be good till 150k, but how about that filter?

Do what you want, it's your truck, but I can state that my truck is shifting much better with fresh fluid and filter at 43k....and I feel that I should have changed it at 30k.