COMING FROM THE RADIATOR TOP OR BOTTOM DOES ANYONE KNOW WHICH ONE IS RETURN LINE!!!! I HAVE 2005 XJ8L!! THANKS A BUNCH AHEAD GUYS ,,im GOING TO INSTALL A TRANNY COOLER SINCE MY LINE IS LEAKING ANYWAYS!!!

 

I'm not sure what you are trying to say. The cars already have a transmission fluid cooler as part of the engine coolant radiator. So have you got leaks, and where if you have ?

Unfortunately, my Technical Notes doesn't say which is the return line, it just shows two pipes, one going in at the top and the other at the bottom, both on the LH side of the radiator. The two pipes each have a flexible section.

I suspect one of the lines is leaking, so you just replace it, no sweat !

 

As Fraser points out, you already have a cooler and to my knowledge it needs no help or improvement. As far as the lines, you will need to replace those to stop the leaks. When your new ones arrive, you will be able to determine which one is the top and bottom. The longer line with all the extra bends snakes up and connects at the top of the cooler. If I recall, this line ends up being the bottom once you get back to where both lines connect into the trans.

Before you remove the old lines, scribe a "T" on the end of the plug connector of the top line. Use an awl and not a Sharpie, the fluid will remove any marks quickly. Once you get the old lines out, it will be obvious which is which. Scribe another "T" on the new top line and you are good to go.