Earlier this year I posted about a heating and cooling issue I was having. Someone mentioned I may have 2 separate issues. I do. I fixed the A.C.. But now that cool weather is coming I have very little heat again this year. Since I already had a hole in the plenum box I am able to feel the heater core. The upper 2/3 of the core is getting quite hot. But the bottom 1/3 is like warm at best. Is this a clogged core? I did a complete coolant system flush earlier this year. Do I need to flush the core? How the heck do I get those hoses off the core at the firewall? Thanks

 

if yours is like mine and you arent spraying coolant when the defroster is on do not replace it, first it is a MAJOR PITA, it took me my dad and brother 13 hours to replace, and i still have extra screws.... the simpliest way i know to flush a core is to find the in and out tubes(they will be coming from the firewall and should be the only 2. disconnect them, put a catch bottle on the lower(anything that will hold coolant(ive used milk jugs before, or if your like me and want it done majorly, go buy a bigger piece of hose and clamp it on to the lower line, then put it into a 5 gal bucket or whatever you would like. take your garden hose(yeah yeah i know, its not recommended but it works) and put it on the top hose, then let her rip, even with doing a full flush youll be shocked at what comes out, if you wanna go extreme buy a 3 day chemical flush beforehand(you'll have to do a full coolant swap with this method though). or you can empty the core while the hoses are off and plug the bottom and fill the heater core with the chemical flush and repeat the rinse process. when you see nothing else coming out of the core let the hose water drain out, plug everything back up and fill your coolant back up, then turn her on and let her heat cycle till the thermo kicks in and if all worked...youll have good hot air. or if you want the uber lazy method, chem cleaner, pull out the thermo, drive around a little bit and then do a coolant flush again and put the thermo back in).

 

While pushing in on the hose with one hand, use finger and thumb on other hand to squeeze in and hold in the two white plastic "ears" on the retainer. Then pull back the hose, turning it some as you do it helps, while continuing to fully squeeze in on the retainer ears.

I found I could not do this standing next to the truck leaning over the fender.
I laid an old rug over the radiator header and engine/passenger fender, stepped up on the bumper, and laid sort of chest-down on the rug, with my feet hanging off the front of the truck. My left elbow might have been on the top of the battery, don't remember for sure.
Very graceful truck ballet
But it allowed me to see it, and get both hands on it at workable angles.