To replace a transmission cooler line, first secure the vehicle on a level surface and then locate the transmission and radiator cooler hard lines. After removing the cooler hard lines, attach the new ones and fill the transmission with the proper fluid.
The tools needed to replace a transmission cooler line are a flashlight, drain pan, floor jack and screwdriver. In addition to the new transmission cooler line, a mirror is recommended. Safety glasses should also be worn when working on a vehicle.
After securing the vehicle on a level surface, make sure the vehicle won't roll or lean while it is jacked up. Using the floor jack, raise the front of the vehicle and then secure it with jack stands on both sides. Next, find the transmission cooler hard lines that run into the radiator and check them for leaks before disconnecting them and draining the fluid into a drain pan. Also disconnect the transmission cooler hard lines from the transmission and drain the liquid into a drain pan.
Next, replace the original cooler lines with new ones. Attach the new cooler lines to the radiator and transmission, as well as any hangers from which they might have been suspended. The transmission should then be filled to the proper level with the fluid recommended by the owner's manual. Once this is complete, start the vehicle and road test it to ensure that there are no leaks around the cooler lines.