[Walt Fricke]

Gordon - the overflow system is a vent - the line you have to pinch off if pressure bleeding. At least for the SCs, with their boosters, same deal. It may be that much newer cars have the vent in the cap (like my race reservoir with the bellows, from which overflow isn't really possible)- the Cup cars I inspect at races often have some cloth held on around the cap with a rubber band, so maybe the vent system on that reservoir is just in the cap and can weep under high G loading.