Cutting the tubes on the old heater core, and new heater core, and then splicing the "repair" is hack work and not a properly performed replacement procedure.

Any dealership whose service department encourages that kind of repair should lose its franchise. There is no telling what other shortcuts are being taken in other repair work.

 

HY had a good suggestion awhile back that i haven't tried yet. after cutting the heater hoses and backflushing with water or CLR or whatever, instead of using the straight splice tubes - use the dorman/peak/preston flush Tee with the screw on hose cap. that cap provides a top off/bleed valve at the high point of the system. some are black, some are ugly yellow. you can them at a variety of prices.

dorman T from advance. #47120 or #47153 for $1.50, not including clamps
http://shop.advanceautoparts.com/web...Term=flush+kit

 

so i flushed the heater core out, fired it up and when it was parked idling it blew warm air after a few. warm but not screaming hot. the next morning tho, of course its back to not working almost like theres no flow but if that was the case it would be overheating right? i also noticed if im driving for a little and park it. then fire it up in a few the heats warm at first till i start driving. any ideas? when i flushed it i made sure to keep a finger on the lines so the core stayed full of water

 

It is possible you still have some air in there man. How did you perform your flush?

I know I had air in my system, even after reconnecting the heater core lines and topping off, I ended up putting another half gallon in. I was only able to get that in AFTER I pulled up on a hill though.
I parked the truck with the nose up on the incline to get the radiator above everything else, then I poped the rad cap off, and ran the truck for a few minutes, revving it slightly for a short time, then checking the radiator and adding when the level would go down. I got A LOT of air out of that system that way.
Now my air is finally getting hot in the cab! Unfortunately though after I did that I must have bumped an old vacuum line, because now my vent selector **** wont change the air flow, its stuck on defrost I have that to wrestle with now...

I suggest a similar method to be sure you have no air in there. Generally, you would get a lil warm at first and then go cold if you had air in the system. The heater core will get some hot coolant in it, then when you start driving you circulate everything under higher pressure and push air up into the core, which wont keep it hot, so it goes cold right away on ya. Just my two cents.

 

Just recently, being seriously tired of being cold in my truck.... I took both heater hoses off, one at the splice on the passenger side, and pulled the other hose off the tube from the water pump. Backflushed the heater core with my garden hose till it ran clean. After that, I put both hose ends up as high as I could get them, and poured water into the longer one. (drivers side) When water started coming out the other hose, I pinched them both off, and reinstalled the hoses. My heater will now bake me out of the truck. MUCH better.

 

i did it just like HeyYou but had my buddy hold a finger on the driver side and i held a finger on the pass side and we put them back on. ill try it again tho and hold the hoses up this time and make sure all the hoses are full of water.

 

going to give this a try.. hopefully i can get my heater going

 

Hello, new to the site here. I thought I would offer my advice based off of my recent heat loss experience. I had air trapped in the heater core. I could hear a gurgling sound at times. I installed a bleeder valve in the hose leaving the heater core and bled out the air. That got rid of the gurgling. I had also previously installed a fail safe thermostat. 10 minutes after I installed it, it tripped and was stuck open. I replaced it with another thermostat and I now have heat. Engine was running at 130 degrees, and now it's up to about 170. I have seen on this site before that many people suggest the Stant thermostat. I'm going to try one of those to get the heat up a little higher. Don't know if any of this helps, but figured it would hurt to add.

 

The bleeder on the top of the exit hose was something else I had considered. I pulled both heater hoses, and just backfilled. As I suspect I am going to be in to my cooling system again soon, I am going to install one of the 'adapter' t's for flushing the cooling system right near the core. Make my life a bit easier.

 

I was a able to successfully back flush my heater core. It definitely worked seeing that I now have hot air coming from the vents but I definitely smell the coolant. From what I've heard "If your vents smell like maple syrup than you need a new heater core"..Is this the case? Is it bad to breathe in that air? Lol Thanks for the help, as of right now I still use the heater because its too damn cold