Transmissions are subject to extreme temperatures that, left unchecked, can quickly destroy the transmission. To prevent this, automobiles use transmission fluid to dissipate the heat produced by the transmission. The transmission has no means by which it can cool the fluid, though. For this reason, a transmission uses two cooler lines, which connect the transmission to the vehicle’s radiator. The transmission fluid flows to the radiator, where it is cooled, and then back to the transmission. These cooling lines are of substantial importance, which is why it is necessary to remove the lines if they become damaged.
Park the vehicle on a level surface and turn the engine off. Allow the transmission to cool down. By the time the transmission is cool, the transmission fluid will have drained to the transmission pan at the bottom of the transmission. Because the two cooler lines are located above the transmission pan, the fluid will not have to be drained to remove the lines.
Raise the vehicle with a floor jack, supporting each of the vehicle's four corners with a jack stand.
Position a large oil catch pan underneath the radiator, under the ends of the transmission lines. Both lines attach to the engine side of the bottom of the radiator.
Turn the fitting at the tip of each transmission cooling line in a counterclockwise direction with a flare nut wrench until the lines can be pulled off of the radiator. Remove the transmission cooler lines from the radiator and allow any excess transmission fluid in the lines to drain into the catch pan.
Locate the transmission cooling lines' connections to the transmission. Where the two lines connect to the transmission varies from car to car, but generally the lines are on the driver’s side of the transmission. Turn the fitting at the tip of each line in a counterclockwise direction with a flare nut wrench until the lines can be pulled off of the transmission. Remove both radiator cooling lines from the transmission.
Slide the two cooler lines out from underneath the vehicle.
