Transmission Cooler, Which Line is Which?

[G202Go]

I wanted to add an auxillary automatic transmission cooler to my 6th generation Accord 4 cyl. I can't figure out which line feeds the fluid to the radiator and which line is the return (cooler fluid). I did a search and couldn't come up with the answer. Does anyone have any idea which line is which? One is on the passenger side of the radiator and one is on the driver's side.

[BullShifter]

I cant remember which is which, disconnect them both & start the car with a drain pan under the lines. Only run it until you figure which is which - 30 seconds max, I would hope.

[G202Go]

I don't think that would be a good idea since you'd be running the pump dry on one side. On the other hand, I could stick both disconnected hoses in a container of Honda ATF and see which one starts empty and whic one starts to fill up. Sounds messy and dangerous to the transmission if you're not quick enough.

[BullShifter]

That's why I said 30 seconds max, it should take 1 second to figure it out . . . .

[accordztech]

it will take no more than 10 seconds to find out trust me i know...

[G202Go]

I think I found the answer here. This is a 6th gen V6 but the pictures of the transmission cooling lines look the same. He hooked up his cooler to the driver's side hose. Later on because of the freezing temperatures, he switched sides.

6th Generation Trans Cooler "How To"

[G202Go]

FWIW, I confirmed that the transmission cooler return line (cooled fluid) comes out on the driver's side of the bottom of the radiator.