don't fully tighten it, attached some clear hosing and put in a container. Fill the MC fluid reservoir and start pumping away -- monitor the clear hose for an absence of air bubbles - once done tighten the SB. Repeat same procedure for engine bay topside bleeder port using a 2nd SB valve....
SB is just a 1 way valve - let's fluid come out but keeps air from getting sucked back into the system....