Greetings all you Dodge techs.
I have a questions regarding the heater core on a 2004 Dakota.
Currently, it's not leaking enough to notice any major loss of coolant. There is some slight seepage on the carpet but not enough to form a puddle or to be even visibly wet. However when i use the heater there a slight smell of antifreeze so it is at least seeping somewhere.
This has been the situation for nearly 8 years. LOL
I have researched replacing it but at finding out i have to remove the entire dashboard i am not inclined to attempt that just yet. I have considered adding stopleak to the coolant but i don't want to negatively affect the cooling of the engine.
What i would like to know and understand is just WHERE that leak most often happens so as to better understand what is going on. Is it on the core itself or from the connectors?

Your knowledge and experience is much appreciated.
Regards.

After doing some research it appears that one of the main culprits are the O rings at the connectors that are in side of the heater box inside of the cab.. they tend to fail. the two piece connector is also a bit of a design fail. And apparently the O rings and connector tubes are not generally included in the heater core purchase.

 

Connectors should be all external. If you have a coolant smell inside the truck, that is quite likely the heater core.

 

I don't know what a factory core looks like, but if it uses a swivel type pipe, most aftermarkets do if its been replaced, this is the most common leak point for me, secondly is just old age from any of the joints could be leaking, or it could have corroded/rubbed through. A properly installed core should have the connections outside the cab, unless the tube was angled in a way to promote the coolant running back into the cab, a connection leak should be visible and stay outside the cab

 

An I've heard the steering has to be loosened too but maybe you can get around that ..I need to change mine out soon too due to it fogging up the window, but for now I just pulled the heater hoses off at the engine side an connected them together, bypassing the core an no fog now...that's temporary of coarse. ,but you can test your entire cooling system ,with a pressure tester, that way, an know if you have coolant leaks in any other areas also ...An that prevents your wet carpet, for now, too..

 

Modern stopleak has come a long way but if you use crappy stuff (such as Bars Leaks) you can get crappy results. Also, if you start with a system already full of gunk and near clogging anyway...well, I'd say don't use it. I'm currently running stop leak on mine and it's working. At first it would only seal after the coolant reached full temp, but after two RT drives from ATL to Orlando, it seems to be sealing better now. Gonna run it till summer, then drain out all the coolant w/stop leak and add pure coolant. I also used stop leak to fix a head gasket leak over ten years ago and am now currently at 350K. So I've saved myself from doing a head job and pulling the dash (so far). Heater is extremely hot and no clogs.

https://dodgeforum.com/forum/2nd-gen...core-leak.html


Anyway, this is a good video for seeing how the core is installed in the heater box. You can start from the beginning if you wish but I've timed it so you can see that the new core can come with the pipes too.