Faulty Radiator Cap
Radiator caps are designed to maintain cooling system pressures in the range of 12 to 15 PSI. When an engine is shut down, the coolant temperature begins to drop. If the vacuum valve in the radiator cap fails, the resulting vacuum in the cooling system can cause a radiator hose to collapse. A malfunctioning radiator cap can also constrict coolant flow. When this happens, the water pump, trying to draw coolant through the lower radiator hose, can create a vacuum sufficient to collapse the hose.
GrassCat III, 1994 Montero 5 speed stock ( for a little while ).
GrassCat II, 1998 Montero with winter package. All the bells a whistles. Ran off with Hector.
GrassCat I, 1991 Ran off with Justice R.