Heater Core Question

[Levinz11]

Wife was driving our 2003 V8 today with defroster running, dropping the kids at school and running errands. She sends me a few photos of coolant leaking from the truck. It seems to be coming from the HVAC drain line. I'm at work and not with the truck. Its too much to be condensation from running the AC. Going to assume heater core is leaking.

Replacing the core is a BIG job. In the meantime...

-Does coolant run through the heater core when not in use?
-If so it can be bypassed, right?

 

[AuSeeker]

Wife was driving our 2003 V8 today with defroster running, dropping the kids at school and running errands. She sends me a few photos of coolant leaking from the truck. It seems to be coming from the HVAC drain line. I'm at work and not with the truck. Its too much to be condensation from running the AC. Going to assume heater core is leaking.

Replacing the core is a BIG job. In the meantime...

-Does coolant run through the heater core when not in use?
-If so it can be bypassed, right?

Just an FYI the AC drain line exits out in the passenger's side wheel well above the frame close to the firewall, if the coolant is leaking there it would be dripping down on the frame.

Yes the coolant constantly runs through the heater core, the blend door either directs the fan to blow through the AC evaporator or the heater core.

To bypass the heater core you would have to remove the heater hoses from the heater core under the hood at the firewall or engine and join/loop them together or just plug the ends of both hoses.

If you at some point in time choose to replace the heater core I would also replace the AC evaporator at the same time since the entire dash assembly has to be removed to do either and the AC evaporator has been known to develops leaks in these 4th Gens.

 

[Levinz11]

Just an FYI the AC drain line exits out in the passenger's side wheel well above the frame close to the firewall, if the coolant is leaking there it would be dripping down on the frame.

Yes the coolant constantly runs through the heater core, the blend door either directs the fan to blow through the AC evaporator or the heater core.

To bypass the heater core you would have to remove the heater hoses from the heater core under the hood at the firewall or engine and join/loop them together or just plug the ends of both hoses.

If you at some point in time choose to replace the heater core I would also replace the AC evaporator at the same time since the entire dash assembly has to be removed to do either and the AC evaporator has been known to develops leaks in these 4th Gens.

Thanks for the tip.

It appears it was a false alarm.

I took a look and probed that drain line and only water came out. I think it may have gotten clogged, then drained suddenly making it seem like something broke. A guy at the store she was at thought it was coolant.