Errr, I'm a V8 guy and not familiar with this engine, but isn't the top hose high pressure hot water from the engine to the radiator? If so it shouldn't collapse unless there's a restriction in the system between the waterpump and top hose, or a reverse rotation pump installed and the radiator is clogged.

A head gasket put on backwards, in some engines, can block water passages and make a restriction. The cylinders would seal normally.