help with identification

Hello all, I am about to purchase a 1979 CX500 custom as my first bike. Bike is running fine, the only issue my friends dad (very mechanically knowledgeable) was able to spot was a coolant leak when we started the bike. the leak can be seen on on the right side of the bike where the water pipe...

Ok so I picked another bike 1980 cx500 deluxe up a few weeks ago it ran ok, however I cleaned the carbs, put a new battery in now and it runs great. question I have is: I know about the mechanical seal/triple bypass. What is this drain tube contraption running from where the mechanical seal...