The radiator is easy to fill, the valve is not really a bleeder and not used, it is more for a pressure test nipple. With the filler at the top most of the coolant system, just fill it and put on the cap, might give it a min or two to bubble up or burp and top off, but I've found that it fills up nicely and no problems. Make sure you use a coolant without ANY silicates at all ! or you will destroy your water pump seal. I use PEAK long life 50/50 premix because it has no silicates and is mixed with deionized water. Be sure to dump and clean the resovoir and fill it to top line as well. It would not hurt to make sure the cap is still in good shape and thermostat is working before filling it up.
'97 VN1500 91 Cubes Of Custom CLASSIC
Vance & Hine 2to1
engine, forks, ignition & carb mod's
WebCam cam & rockers hard weld & grind
NEW TOP END, NO LOOKS ALL GO GO
Maxx intake manifold system & super G carb 44mm