Ford 6.0L Super Duty Transmission Cooler Line 4C3Z-7B028-CA

This is a replacement transmission oil cooler line for Ford 6.0L Power Stroke diesel trucks with the 5R110W TorqShift automatic. It replaces Ford 4C3Z-7B028-CA and 3C3Z-7B028-CA and is listed for the 2003-2004 F-250, F-350, F-450 and F-550 Super Duty and the 2003-2005 Excursion. The line is a formed steel tube with a crimped section of rubber hose, and it connects the remote transmission filter to the passenger side radiator fitting.

On these trucks the rubber section and crimp are the weak spot. Heat cycling cracks the hose and the crimp starts to weep, so the usual signs are ATF on the passenger side of the engine bay or on the frame rail, a fluid spot under the front of the truck, and a transmission that runs low on fluid. Low fluid on a 5R110W leads to slipping, flare shifts and overheating, so a leaking cooler line should not be put off. Clean the area and run the engine to confirm the leak is at this line and not at the filter housing or the radiator fitting.

To replace it, let the transmission cool, put a drain pan under the front of the truck, and disconnect the line at the remote filter and at the radiator fitting. Unclip it from its retainers and remove it. Fit the new line into both connections until they fully seat, reinstall the retainers so the hose cannot rub on anything, then top off with Mercon SP. Start the engine, check for leaks at both ends, and recheck the fluid level at operating temperature.