Water is leaking and hissing coming out the top of the engine on 2001 Chevrolet Lumina

returning to the water pump. no water in the oil???

Asked by for the 2001 Chevrolet Lumina
"Top of the engine" is not much info. There are tubes, hoses and fittings all over and leak could be anywhere. Have a shop pressure test cooling system and see exactly where it is coming from.
There is a pipe that comes off the top engine goes to rubber then to thewater pump. The leak is right at the beinging off the pipe as it comes off the engine, you can hear and see. Question can that pipe be replaced with
pulling all that suff on top of it.
Sounds like a threaded fitting that the heater hose plugs in to and the seal that seals around the tube of the hose where it pushes in is corroded and leaking. You can purchase the threaded fitting for replacement but normally the fitting breaks off when try to unthread from engine. Spray penetrating fluid at the base where it threads in at and let soak and spray again for a couple days before attempting to unthread. If it breaks off then you have to get in there and chip the broken pieces away from the threads to allow for replacement.