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).
The heater hoses are 5/8 inch diameter.
The 1999 Chevrolet Camaro heater hoses will have a swivel nut on each end of the hose. Turn the swivel nuts to the left and the heater hoses will come off. Reverse the process to install the new heater hoses.
the heater hoses are on the left side of the engine and will be two next to each other on the fire wall
near the fire wall where the heater hoses enter
The heater core on a 1999 Ford F250 Superduty is replaced by removing the heater hoses, disconnecting the wiring harness, and removing the retaining bolts. The cover can then be removed, the heater core unbolted, and removed from its housing.
Drain the radiator..Disconnect the heater water hoses from the heater core.Disengage the stops and lower the glove compartment door.Remove the electronic blend door actuator and bracket assembly.Remove the screws.Remove the heater core cover.Remove the heater core.Follow the removal procedure in reverse order......
The 1999 Chevrolet Z 71 heater core can be accessed by removing the passenger side kick panel. Remove the heater core water hoses. Remove the heater core retaining bolts. Reverse the process to install the new heater core.
On the firewall, right next to the Power brake booster. If you follow the metal tubes around the engine, the hoses are connected to the steel tubes.
To the best of my knowledge, there is no heater or outside air filter on the 1999 Ford Expedition, and Grease Monkey confirmed that when my Expedition (Eddie Bauer version) was in for service.
Underneath the dash on the passenger side. Open the hood and you will see the hoses entering the firewall where the core is located.
inside the passenger compartment behind the glove box. to find any heater core, open the cars hood and locate the 2 heater hoses. They will go through the firewall and they connect to the heater core.
Check if small water hoses are hot going toward firewall and heater. Fan not blowing? 15 possible problems. Check all fuses.