merc 7.5

[Andre Michel]

I bought a used lower unit and installed it, and filled the gearcase up with oil and then tested the motor, then inspected the gearcase oil and it has water in it. My guess is the seals are leaking, how do find which seal is leaking and will I need special tools to replace them?
Also when I installed forward and reverse are switched what did I do wrong?

The cooling water only dribbles out of the pee hole, seems like it should flow stronger, how can I clean out the cooling system passages, the impellor is fine.