Ford F150 - Cooling loss but how to fix? Easy question...

2000 Ford F-150 5.4L 2WD

Please disregard the first answer below as I changed the question (issue wasn't fuel injector leak).

Okay, here is the modified question:

I finally located a leak under the heater hose casting above the water pump. It appears there is a 1/2" high rubber or plastic seal between the water pump and the heater hose casting. It is leaking coolant out on to the block.

1) Do these normally leak?
2) Can I just use a silicone sealant of sorts to fix this or is this a "must replace" part.
3) What is the name of the casting/part above the seal, where the heater hose connects to that vertical pipe? The opposite end is the thermostat housing.

Here is the new pics:

Thats your fuel injector.

RJJP = Thank you for your answer but I was mistaken regarding the leak at the fuel injector. Once I removed the alternator and got a mirror in there, I found the seal leak in the new pics above. I'm hoping someone will answer my three questions. Thanks!

that would be your intake leaking coolant. That casted metal part is a water crossover tube. Depending on if it is leaking between block to plastic intake, or from plastic intake to water crossover, determines if that water crossover has to be removed from the intake. Either way the intake has to be removed and i would be doing both intake gaskets and the water crossover tube gaskets (not sure on what type of gasket is between there)