Trace the heater hoses back towards the engine. The one that comes out of the top of the engine is the inlet. The one that attaches near the water pump is the outlet.
Rick
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Upper and lower radiator, inlet and outlet heater core, bypass,Upper and lower radiator, inlet and outlet heater core, bypass,
I don't know about the outside diameter of the hoses but, the outside diameter of the heater core inlet and outlet tubes are 3/4" (inlet) and 5/8" (outlet).
Find inlet and outlet hoses under hood usually on the passenger side and disonnect them from heater and tie them together with a coupling and clamps
Heater core? Inlet or outlet hose fitting at heater core?
On the firewall, under the hood, you will find the inlet and outlet hoses.
Remove both heater hoses from inlet & outlet of heater core. Connect these hoses together.
It depends on the vehicle you have. In many cases (but not all) the inlet hose is smaller than the outlet hose.
Couple inlet and outlet hoses together
The outlet from the engine that feeds hot coolant into the heater core is usually (but not always) located close to the thermostat. The return hose from the heater core usually returns into the water pump.
There are two heater core hose that goes to the firewall the inlet and outlet. through that hose, you will also have the rear heater core hose attached to a T joint in both the inlet and outlet hose. You splice the hose of the front heater core inlet and connect that to the rear heater core inlet hose. Same goes to the Outlet hose with the T joint using a conncetor which you can buy at your auto parts store, 3/4 inch size. Basically you are bypassing the front heater core that is connected to the firewall. You wont have any defroster and heater for the front, but the rear vents and control will have heat.
It is called a Heater Core not Cord. It is located inside the vehicle mounted on the firewall on the passenger side. It is buried behind the dash components. If you raise the hood and look on the firewall, passenger side, you will see the inlet and outlet coolant hoses connected to the Heater Core.
Disconnect heater core inlet and outlet hoses - couple them together