Replacing heater core: how difficult?

[terky]

My heater core went out on my 83 diesel blazer. I assume that this is pretty straight forward but i need my truck for work, so i cant have any downtime. Does the heater core come out easily or do i have to remove the dash to get it out? I also have ac, dont know if that is significant or not. Thanks for the help.

 

[k20]

http://coloradok5.com/heatercore.shtml

Its pretty easy, I did mine in about 2 hours. I didnt need to drop my inner fender to get to everything. When you get the heater box out and are taking it apart, there will be like 3 screws you absolutely cannot find.....they are under some weatherstripping.

 

[JimmyJuneau]

I just replaced mine yesterday. Althought it is a cheap part. It is a pain in the ass to replace. This is how I did it.
I started by taking the passenger seat and glove box out. Then I took the passenger side fender bolts out and let it rest on the tire. You have to do this in order to get to to nuts that are holding the two studs in place. Once you have taken the to nuts off there is one more on top. After you have all three of those off you can then pull the heater box out from the inside of the cab. After that you have to take off numerous screws in order to get to the heater core itself. Be careful of the vacuume lines. As I am still not sure what i did to mine. My defrost does not work. I wuld suggest replacing your heater lines whiel your replacing the core. Good luck.

 

[k20]

As I am still not sure what i did to mine. My defrost does not work. I wuld suggest replacing your heater lines whiel your replacing the core. Good luck.

I had that problem and found a vacuum line over the tranny hump, nearer the gas pedal, that had come unhooked.

 

[JimmyJuneau]

How many lines are there? I have heard there are three.

 

[tRustyK5]

Diesel version of this problem adds a step or three. The AC condenser box on the firewall is wrapped with a factory sound deadening rubber. It covers access to all the speed nuts and other crap you need to get to. My '83 has a fuel filter also in the way and needing to be removed partially.

I found if you plan it carefully you can make three strategic cuts to the sound deadener so that it can be removed and be replaced without it flapping in the breeze later.

it took me an honest 6 hours to do mine, but i was anal retentive about bagging each fastener, making notes, and diagrams so it would go back properly. I hate missing screws and clips under the dash as they're always the source of squeaks and rattles and malfunctions later.

Rene