Bypass Hose

Hi all, I'm going to be replacing my radiator, upper and lower hoses. While shopping for the parts on RockAuto, a 3rd hose was shown called a "Bypass" hose, part# ACDelco 14155S. I'm not sure what this is for, where it's located, what it connects, and if I should be changing it out with the upper and lower while I'm at it.

Any help would be appreciated.

Thanks,
Chris

On cars so equipped the bypass hose usually connects to a small port on the water pump and will allow the coolant to bypass the heater core if the coolant level drops too low.

I'd go ahead and replace it if you never have. Chances are it is worn and brittle at this point.

Yep, it runs from the water pump to the intake manifold just in front of the EGR valve.

Thanks, guys!