first post, so i realize i don’t have any cred, but this process i out together worked well. it’s been several thousand miles and it’s donna great. i don’t know if it shifts better or not but i feel a lot better knowing it’s in good condition.
i have an 03 f150 that a friend gave me because it wouldn’t start and his wife wanted it gone.
here we go:fully flush your 4r70w at home with no mess. plan to devote 6 hours to it.
my truck has 180k on it, its trans fluid was brown with what could have been a slight burnt smell so i wanted to change it. i watched a bunch of videos, read the FSM and looked the truck over for fitting locations, etc.
my goal was to do a filter replacement with a full fluid flush. the mechanic i’ve used for things down the street wouldn’t touch it because there are horror stories of whatever method that shops use to do a flush. and i didn’t want to spend $260 for that.
so... i got a cheap plastic hand “siphon” pump from ebay. the hoses that come with it suck so go get maybe 10’ of 3/8” clear (so you can see the flow and color change) vinyl tubing.
then use the pump and new hose with the oil drain suction tube that came with the pump and suck out as much oil as you can from the pan. i got out about 4.5 quarts. i also needed this little pump to not spill anything.
jack the front of the truck up and put it on stands. this gave just enough room to appropriately uncomfortably move around to get the pan off and on.
next remove the pan and cheer that there is only a couple quarts of oil in it and nothing spilled out. clean the pan and magnet and the sealing surface against the transmission. replace filter, mind the hard little gasket that sticks the filter into to the valve body, it stayed stuck in the body. napa sells a kit with the filter and new gasket. the new gasket appears made exactly how the oem was and i don’t know how old the existing one was. put back together.
fill trans with 5 quarts of fluid. i bought 3x5qt jugs from amazon because i wanted reusable jugs and i could only find quarts locally.
remove the transmission cooler return line from the quick connect. location is slightly to the right of center and on the bottom of the radiator. you can see most of the lines and the air:air cooler from underneath. let it empty and leave the oil pan under there.
remove the feed line from the transmission cooler, top drivers side. the quick connect are 3/8” and are specific to ford transmissions. there is a small step at the business end of the key for it to fit properly on the line.
pull the line back and push a piece of 3/8 vinyl tube on it and add a zip tie. put the other end into a 5 gallon bucket and tape the tube to the handle of the bucket so it won’t move. plug the quick connect for the return/drain back in.
my girlfriend helped with the next part. i had her start the engine and click through the gears for about 2 seconds each then shut the engine off.
then add another 5quart bottle. run again and click through a few gears. this is when the fluid turned red going out of the clear tube going to the bucket. i added a couple more quarts and ran it maybe 5 seconds longer. i added 3 more quarts out of the last jug and the level was just on the top of the dipstick. i cleaned everything up, let it idle, checked for leaks, cleaned everything up.
if it had a torque converter drain plug (eliminated in ‘01 i think?), this whole thing would have been a lot simpler, but the method i used worked extremely well for doing a job like this using the transmission to flush all of its own fluid.
it also took quite a bit of time and research to come up with this string of gyrations, so i hope this helps someone else have a bit of a head start.