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.
To replace the heater core on a 1999 GMC Safari, start by disconnecting the negative battery cable and draining the coolant. Remove the dashboard and the center console to access the HVAC housing. Disconnect the heater core hoses from the engine bay, then unbolt and remove the old heater core from the HVAC assembly. Install the new heater core, reassemble the HVAC housing, reconnect the hoses, refill the coolant, and finally reconnect the battery.
To unclog the heater core on a 1999 Ford Contour, start by disconnecting the heater hoses from the engine and the heater core. Use a garden hose to flush water through the heater core in both directions, allowing debris to be expelled. If the flow is still restricted, consider using a specialized radiator flush solution for a more thorough cleaning. Finally, reconnect the hoses, refill the cooling system, and check for leaks.
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 remove the heater hoses from the bulkhead connectors on a 1999 Volvo V70, first, ensure the engine is cool and then locate the hoses at the firewall. Use a pair of hose clamp pliers to loosen and slide the clamps back from the connectors. Gently twist and pull the hoses off the connectors, being careful not to damage them. If they are difficult to remove, you may need to use a flathead screwdriver to carefully pry them off.
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.