Auto transmission cooling lines
 

I had to replace tranny lines on th350 does the top line on radiator go to top hookup on tranny? Someone told me one is pressure line and one is return line and they shouldn't be switched.

Not sure how it is supposed to be...but it doesn't really matter to much. If it is hooked up backwards, it'll just run through the cooler backwards.
If you want to be anal about it, figure out which one is the 'pump out' line, and hook it to the top of the cooler. That way, the fluid can cool a little more than if it were cooled, then run right beside your 200 degree anti-freeze. (that last part is why I don't think tranny coolers should be in radiators...200 degrees is the magic number for accelirated tranny wear)

The original routing is top of the radiator to the the upper fitting
on the transmission. I don't believe that it makes any difference, but we make our own lines and it is easier to route them this way, also.

Jim

Just a thought but If you already have them loose I would plug the radiator lines and just get a separate cooler that mounts in front of the radiator. You can pick them up for around $30 bucks.

Top to top and bottom to bottom, the bottom is the pressure side and you want to keep fluid in the line so that it starts primed. If you reverse it you would drain the fluid back into the trans when you shut down.:bowtie: