My husband has a 05 Vulcan 1600. Last year on a trip he could smell radiator fluid. We found later that it had leaked tho not much. We took it to the dealer and they could only find a loose clamp.
It's still leaking from the overflow tho not a lot. Someone said it sounded like air in the system. How can we bleed it out if this is the case?  

Ride it, it'll bleed itself, just make sure the overflow tank is above the cold line before starting the bike the first time each day. When the bike is running at speed, the air pockets get broken up into bubbles and scattered all through the coolant. Then when the bike is shut off and sets, the bubbles rise and some of them will be trapped above the thermostat, where they will be pushed into the overflow tank by the expansion from the residual heat. As the bike cools, coolant will be sucked back from the overflow tank, replacing the air bubbles. It only takes a couple good rides and cooldowns to remove any air from the system, after the annual coolant replacement.

Since all the mechanic did was tighten the hose clamps, there shouldn't have been any air in the system to begin with, unless you let the overflow tank run dry. However, since that was fixed last year, any air in the system should have worked it's way out long ago. This ongoing problem sounds more like maybe you're overfilling the system. You are checking it when the bike is upright, rather than on the sidestand, aren't you? ...and only filling it so the overflow tank fluid level is above the cold line, when the bike is cold, rather than filling it all the way to the hot line when the bike is cold?

If you're really concerned about air in the system, you can check it when the bike is cold. Just remove the radiator cap from the top of the thermostat housing and see if it is full of coolant. As long as it's full of coolant and the overflow tank is above the cold line when the bike is upright, it's fine, any air in the system is too minor to matter.

regards,
Joe