The red-marked port needs to stay open to the atmosphere. All it does is draw air from inside the cab as the vacuum powers the flapper inside the wiper motor. You definitely DO NOT need the hollow bolt or the hard line to the pump.
Jerry
Originally they would have a rubber hose running from the firewall to the fuel pump diaphragm portion? Thats alot of hose.
My motor has stamped on the ports backside... VT and MAN. Fresh air comes from the green line (port furthest passenger side.)
Red in the pic above is for the washer
