I've got a 2000 F-150 4.2L that seems to have a pinhole leak in the coolant bypass tube (?) situated in the engine valley just behind the thermostat housing. This is a 6" L-shaped aluminum tube that connects to a 5/8" hose that runs down to the top of the water pump. How to repair? Is this tube pressed in? Threaded?

Any advice/help on this would be greatly appreciated.