Vetteman61
Registered Member
Has anyone replaced the heater core. I've got an 87 K5 with factory air, and a very leaky heater core. I've heard you have to take the entire air system out.
CK5
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Heater Core
- Thread starter Vetteman61
- Start date
its a PITA, but doable with basic tools and a LOT of patience. You have to dismantle your entire inside air box, and possibly some of the engine bay air box as well to get the heater core out. To see what you're up for, remove the glovebox. The heater core is behind it, so you need to remove the ducting and controls that attach to the distribution box, and then pull out the heater core. You should not have to touch the AC system... but you may have to pull apart the plastic box in the engine bay (depends)
Part is like $25, labor is probably 3 or 4 hours
Part is like $25, labor is probably 3 or 4 hours
Nothing needs to be disassembled in the engine bay...aside from the heater hoses. However you do need to remove the inner fender to get at the speednuts holding the heater box on. Once those are undone you have to remove all the vents and controls from the heater box and then remove it as a unit from under the dash. The glove box door will need to be removed.
Getting the core out of the box is a bit of an IQ test as two of the bolts holding it in are underneath the foam gasket and are kinda hard to find.
Be glad yours isn't a diesel. The Diesel trucks have a sound deadening cover over the entire firewall and the heater/AC box. It adds a few hours to the job if you want to save it and not disconnect the AC lines.
not that I was in a rush, but it took me 5 hours or so to do the heater core in my 6.2 pick-up with AC.
Rene
Getting the core out of the box is a bit of an IQ test as two of the bolts holding it in are underneath the foam gasket and are kinda hard to find.
Be glad yours isn't a diesel. The Diesel trucks have a sound deadening cover over the entire firewall and the heater/AC box. It adds a few hours to the job if you want to save it and not disconnect the AC lines.
not that I was in a rush, but it took me 5 hours or so to do the heater core in my 6.2 pick-up with AC.
Rene
Thunder
3/4 ton status
Its been a long time since I did mine, but I dont rember having to remove the inner fender on my 89 with AC. Just the heater hoses. That was all I removed the engine compartment. Then take off the glove box and remove the ducting/heater box from the inside. IIRC All the bolts that hold in the heater core box were acessable without pulling fender. Un doo heater controls, Pull the ducting/heater box out. It all comes out as a unit. Undo the small screws that hold it togeather. Slpit the box/ducting and remove heater core. Put in new core then reassemble It wasn't that hard of a job took me 3 hrs taking my time.
You dont have to remove any air conditioning stuff.
You dont have to remove any air conditioning stuff.
BKinzey
1/2 ton status
I suggest pulling the inner fender as well unless you are like the stretchy guy from Fantastic Four. One of the nuts is difficult, the other is torture
Dropping the inner fender takes 15 minutes at most, and doesn't need to come out. I did take mine out but only to clean a few other thing up at the same time...but you can just let it sit on the tire to get the room you need to remove the speed nuts.
Rene
Rene
yeah, inner fender is a 50/50.. it certainly can be done on, the one is a little tough, but if one has the right hand tools it's not hard.. 1/4 drive med deep swivel socket, ext and a mirror and 5 minutes of fiddling...
But yanking the well lets ya clean the area, maybe even throw a fresh coat of black on it too...
Thankfully, I never have to deal with that again...
But yanking the well lets ya clean the area, maybe even throw a fresh coat of black on it too...
Thankfully, I never have to deal with that again...
FormulaGT
Registered Member
Been there, done that! No way around it but the job is a pita. I think patience is the most useful tool you can apply and you'll be fine. I think it took me about 1/2 a day and a lot of interesting words added to my vocabulary.
Good Luck!
Good Luck!
I changed mine in my 89 in an hour. Nothing under the hood needs to come apart other than the heaters hoses must be removed. As for the fender well, i was able to remove the one hard to reach nut using a swivel and extension.
I used the write up that used to be on here. I just searched and couldn't find it now though. I sent you an email through here. Email me back and I will send it to you. I saved it on my computer.
Rick
Rick
rick88blaze said:
http://coloradok5.com/heatercore.shtml
That one? Everybody forgets the "tech article" link from the main page
-- A
Yup, that one. I was looking in the Tech Articles forum. 
Rick
Rick
Go ahead and pull the fender. Adds about 15 min. tops and gives you a chance to clean all the years of debris and mud/sand out as well. I recently replaced mine and it only took me about three weeks.
Of course I pulled all of the duct out and cleaned everything since it was an AZ truck and full of a 1/8" layer of dust.
Word of caution though, Be careful with the bolts that go through the firewall. These have a retainer clip built into them and it is the only way to attach the bolt to the box. These are not made anymore.
You also might pressure test the new core before reinstalling everything. Somebody else here had to install 3 or 4 new ones before he got one that didn't leak.
Good luck and use Rene's tech article.
Of course I pulled all of the duct out and cleaned everything since it was an AZ truck and full of a 1/8" layer of dust. Word of caution though, Be careful with the bolts that go through the firewall. These have a retainer clip built into them and it is the only way to attach the bolt to the box. These are not made anymore.
You also might pressure test the new core before reinstalling everything. Somebody else here had to install 3 or 4 new ones before he got one that didn't leak.
Good luck and use Rene's tech article.
That's not my tech article, it was written by Eric Hummel (AKA Grim Reaper) a few years ago.
Rene
Rene
BKinzey
1/2 ton status
Mine was a diesel and had some sound deadening panels to remove I'm sure it's easier without them. We didn't remove the inner wheel well and it took us, 2 guys, about 4 hours.
tRustyK5 said:
I knew it was a mod that wrote that, I just didn't go back and look to see. Sorry 'bout that.Vetteman61
Registered Member
thanks
Thanks for all the help guys. Not looking forward to it, but at least I'll have the experience... and heat!
Thanks for all the help guys. Not looking forward to it, but at least I'll have the experience... and heat!
BulldogK5 said:
Nothing to apologize for, I just wanted credit to be given to the right guy.
Vetteman, just take your time...and if you have to, take some pictures as you disassemble the stuff under the dash. It's so much nicer if every fastener and clip goes back.
Rene
You might also use a sharpie marker or some colored tape to help mark the threaded rod that opens one of the doors. There is a plastic retainer that holds the arm for the heat/air door. These are notorious for breaking somehow, and they are apparently not made anymore either. That's o.k. though, if yours is broken I can e-mail you some pics of what I did to fix mine. It was very simple.
