what is the pipe going into the water pump on my car.It goes into the big inlet

Sounds like your talking about by-pass hose tighten up the hose clamps see if it stops leaking. Note: that motor has timing cover coolant leak issues.

the lower hose has a steel pipe that joins the lower hose to the water pump. the pipe does rot out. it can be replaced. it has one bolt holding it along with the 2 clamps. Roy