Originally Posted by Tajohns34
They sell heater core flush but it is like $20 - $25. I think CLR is like $6.
Here's an update:
Yesterday I flushed the heater core again with water.
Per Tajohns34's suggestion, after flushing I filled the heater core with an off-brand "CLR" I purchased from The Dollar Tree for $1/bottle.
*Of course using the off-brand was my choice, not Tajohns34's suggestion. I was comfortable with the product though because I'd used it before and it performed (and smelled) the same as CLR.*
I used two bottles to be sure the heater core was full, and let it sit for about 8-9min.
Then I flushed the heater core again with water. I noticed a little more dark crud coming out than there was when I just flushed with water.
Lastly I refilled the heater core with Dexcool, reconnected the hoses, and ran my truck with the radiator cap off and heat on while revving the engine and squeezing hoses to "burp" the system.
The heat not only worked, but it was hotter than it was before I had my radiator replaced! Ran the heat for quite a while yesterday with no changes. Ran the heat this morning, and it's still working!
Thanks for all of the help!!!!