JOESPIFFY

which line is in and out on trans cooler. top and bottom. Is there a better place to disconect discharge line,and how to locate it? 1986, 700r4 trans? trans fluid flush.

383vett

Upper line fluid in, lower line fluid out. These are the lines going into the tranny, not the cooler. You'll have to trace them.

PatternDayTrader

I don't remember but its the lubrication circuit so its critical you get this right.

zachaeous

On my 1984 the top cooler line on the radiator was the in and the bottom line was back to transmission. I removed the bottom line and screwed a fitting I had made up with a hose on it into a drain pan. Then I started the motor and started putting fluid in the filler hole as the fluid drained out into the drain pan.

I marked my drain pan in gallons and added fluid in the same amount as I drained out. I stopped filling and shut off the motor when the fluid started looking bright red that was pumping into my drain pan.

Topped of the fluid level after hooking back up the cooler line. I also made sure the transmission was up to operating temperature before starting the flush.

I changed the filter prior to flushing the transmission fluid.

Good luck with your job.

PatternDayTrader

I suppose that's one way to do it, although the entire time the engine is running and the trans fluid is flowing into the pan, the transmission itself is not being lubricated.