The hose coming off of the top driver side of the coolant reservoir.
I have heat, the auxiliary pump is working. The radiator fan is working, I have no reason to believe that there is a head gasket failure, but there's clearly some type of pressure on that hose where it connects to the expansion tank.
I have searched my narrow *** off and I can't even figure out what it goes to. If someone could help me understand it's function and hopefully the problem, I would greatly appreciate it.
Thanks!!


