[Rhino404]

You dont loose much, as fluid only circulates through the cooler when the engine is running. There is some residual in the lines but again, not very much. If you need to top off with ATF stick with Nissan branded. Check fluid level with the dipstick...be sure to use the correct side of the stick (hot or cold) based on engine temp.

 

[04BlackTitanLE]

When I did this I just topped it off with valvoline ATF. I read the back label and it said it was compatible with Nissan Matic-J and S. No problems yet and 10k later.

 

[Marlin]

Yea replace the line ASAP. I replaced my 2 long ones and they were leaking a little already. Not dripping but everything undre there was coverd in sticky dirt.
And I used Valvoline Max-Life trans fluid in my truck. If you have more than 50k on your fluid I would also doa drain and fill. So drain the trans fluid out, drain plug on trans pan. Then replace lines (get new clamps as factory ones are not good). Then fill back up with Max-Life.

My truck shifts better now and I am not to worried about the trans lines.

 

[bestatchess]

If you are disconnecting cooler lines anyway, you are 10 minutes away from changing all the ATF by draining from the cooler return line while refilling.