Hi looking for some quick advise , We have Geileis a 1995 mk11 C36 with the m35 engine can anyone tell me what hump hose size i need , Tried Catalina direct and they need internal size ,but on ours someone has fitted solid hose and its leaking and gunked up with silicone so will have to cut it off but need the new one there ready to replace as we use her all year round 
can anyone help 
cheers Kenny