Was replacing the coolant filler neck yesterday and decided to flush the heater core too.

I disconnected the rubber hoses where they connect to the metal piping on top of the motor, vs at the firewall. A tapered hose nozzle works really well for this. Ran water with low pressure through both ends and I didn't see any crap coming out. I had flushed the whole system with chemical flush back in 2013 and back then, I did see crap exiting with the water.


Heater hose connections by the air hat...




Anyway, I stuck a funnel in one hose, added some Peak radiator flush (diluted half and half with water) till it started running out the other end, then I plugged it. I let it sit for over an hour while I washed the cars.
I then flushed and back flushed again, first with tap, then distilled water. I used my mouth to blow air through the core and get rid of the water. Filled up with fresh coolant and reconnected hose. Ran truck with cap off to get rid of air and that's all she wrote.

Heat is so hot, I can't hold my hand in front of the vent for more than five seconds on full blast, full hot.


On another note:

I've thought of adding a 1" valve to one of the hoses, so I can shut off flow to the core during the summer and hopefully boost AC performance. Anyone know if stagnating the coolant might cause issues? (I only use straight coolant and distilled water).

 

Shouldent had my heater core shut off all summer with no problems just turned it back on last week tested lots of heat.


But you may have a different outcome if dealing with extreme cold cant say.


If worried flip the flow back on every three weeks for a bit then shut it back off.


I think most clogs happen because the OEM heater core is very very thin and prone to clogging the aftermarket cores are twice the thickness and flow way better you must snap off the plastic hold down pegs to fit the thicker aftermarket core in no problem easy to do.


Im talking about a 97 to 2000 dakota

 

Cool vid on pulling the dash to remove the HVAC box this shows the thin heater core. You can get a longer perfect fit core thats thicker also so ignore that crap.


This shows a 99 Durango but exact same dash as a 97 to 2000 dakota

 

Thanks. I remember what you went through. That job is exactly what I'm trying to avoid ever doing. You had the heater core shut off... the new core? Why?

 

To get the coldest air flow all summer long


I don't know what's going on with this forum but I cant post any pictures anymore its getting me HOT under the collar. ???

 

Same thing happened to me. I tried posting, it all looked good in the edit box, but the picture never showed up.

 

OP you might want to check your A/C too. The unit on my 3.9l '97 Dakota will run you out of the cab. But I think my heater core is stopped up some because heat is tepid and if the defrost is on, non-existent!


I'd love to hear more discussion on the best way to clean the crud out of the heater core without flushing a leak. I too was thinking of a flush kit with water, letting it sit for a while, then flushing with low pressure from a garden hose.


Sound about right?


Thanks.

 

That's what I did. I cant think of any other way to clean out the core. Haven't done a thing with the AC since I've had the truck. Remember not to use a lot of pressure. Turn the water low from the spigot, so you can't screw up.

 

USE CLR..IT WORKS!!..Id done 8 clogged heater cores and now they will roast you out of your car or truck..lol..Seen it on you tube..deconect both hoses..get a funnel and pour CLR and let it sit for 15-20 mins..then por water threw it to flush out the CLR and then use your air hose from your air compressure the blow the water and crud out..Blow the air both ways..reconect the hoses and add coolent then your good to go..

 

Got this done.... here is the link...

https://dodgeforum.com/forum/2nd-gen...e-install.html