MotoGP God
Posts: 18,275
Join Date: Apr 2002
Location: Oxford
Mood: Its ONLY a Bike Club
Last time I remember a mate having a head gasket go it pressurised the header tank and was blowing coolant out of the overflow.
Depending on which hose came off it may be worth looking at the thermostat, if it failed to open then it could cause the pressure to build up in the system.