im having a little problem with my 97 gtp it seems i have no coolant going to either one of my hoses neither upper or lower and when i hit the throttle the lower hose collapse's .... i changed thermostat and flushed radiator and i know radiator is not clogged cause during flush water came out both ends .... now when i drive the car stays at about 180* but as soon as i stop it climbs up to about 240* almost in the red zone ... could this be a bad waterpump ?

thank you ahead of time for your answers