Heater core replacement procedure '99 S10?

[3LIT3]

Is this a job that should be taken to a qualified mechanic ? Or can a first timer do it himself ? Anyone know about how much this would cost to replace? I recently noticed steam coming through my vents .. so I assume that my heater core has gone bad .
ANY thoughts are appreciated !!!

[yellonoma_ss]

It's a strait forward but very time consuming procedure. I have recently done mine alone (first time, I popped my heater core cherry) and it took about 5 hours no breaks (mine is a 96 thou, alittle easier).
I think it is well worth it to do it yourself as it would probably cost well over $500 to get it replaced professionally, compared to a day of your life, $60 for a new core, alittle blood and loosing your voice from cursing so much. Plus your not a real man until you've changed a heater core in a S10 .

You don't need very many tools either, for a 96 dash all that is needed is a phillips sdriver, flat sdriver, 10mm, 15mm, 5.5mm, 7mm w/ratchet, lots of extensions and a torx set.

[01x.joyride]

i did it myself and im no genius here...mine was an 01...spent the weekend on it just last weekend...didnt know what i was doing and/or exactly what i was looking for...but i did it...took awhile...several breaks...several too many f bombs...but its all good...you save a shitload doing it yourself....i spent 59 bucks, 53 for the heatercore and 6 bucks for an extension i needed...instead of 800+ the dealership wouldve charged....those assholes.

and i pretty much used the same tools yellownoma used...as well as a 13mm....both wrench and socket

[Dr Evil]

I just did mine in my 99 a couple months ago. I had mine done in no time, maybe 3 hours total time spent working. I used to be one of those pricks at the dealership though

I've got a few pics I took of the process if you want me to send em your way let me know.

[Kampz69]

Quote: Originally Posted by Dr Evil

I just did mine in my 99 a couple months ago. I had mine done in no time, maybe 3 hours total time spent working. I used to be one of those pricks at the dealership though

I've got a few pics I took of the process if you want me to send em your way let me know.

post them on here, I know I'd like to see them. mine will go bad soon im sure lol

[Dr Evil]

I dont have anywhere to host the pics at but I could email em to you. Or someone not as lazy as me who has a photophucket account could host em

[badjuju342]

It's not that bad , did mine the Sunday of the Daytona 500 on the '96 Blazer , plus flushed the entire cooling system and a few other repairs and made it home in time to see the fifty laps of the race. Started on the Blazer about 10:00 in the morning.

[Dr Evil]

Step 1, arm yourself with at least a 12 pack of your favorite adult beverage. I prefer Yuengling lager or something similar. Natural ice works too. I did half of mine one day. The reinstall the next. Total time working was just about 3 hours or so. This is my first write up so go easy and dont flame me too bad guys.

Remove battery. Remove the glove box. Remove under dash trim/hush panels. Remove speaker covers and screws underneath, defrost vent difuser and screws under it that hold the dash to firewall. Its a good idea to leave one or two in till you're ready to remove the entire assembly.
Remove the bolts holding up the steering column. Some like to remove it all-together. I just loosen everything up and drop it down onto the seat.
Jack front right of truck up and remove right front wheel. Remove inner fender. To remove the inner fender you'll have to loosen the PCM nad part of the battery tray and a few other misc bolts. I didnt remove my inner fender all the way, just enough to be able to reach through and work at the firewall.

Drink beer, admire your work thus far.

You'll need to remove a couple of 10 mm bolts at each end of the dash assembly in the lower corners. Here is where it can get tricky. When I do this I do not remove the radio, inst cluser, hvac controls...nothing. I get under the dash and disconnect everything that I can which is everything but the radio as best I remember. You'll need to disconnect the main elec block on the drivers side (7mm) in the center of the connector there is a bolt. Loosen it, pull it out. I remove the BCM too. While I'm there I also disconnect the vac lines to the HVAC stuff, air bag connectors(yellow) etc etc.

Once you're sure that things are disconnected step back and have another beer or three.

Remove the aforementioned screws at the top of the dash and the entire dash should rotate down/back. The entire assembly sits on two locating pins at the base of each A pillar and the frame for the dash is slotted to fit in there. You'll know it when you see it. I rotate the dash down and lay it on the seat/steering column and reach behind it to disconnect any other wires such as the radio wires and antanae wire as needed. Once you're satisfied everything has been disconnected grab a buddy, gf or wife and kift and remove the dash. You'll be left with firewall, a bunch of wires, a few hoses, a big black box looking thing and a steering column laying on your seat. This is normal.

Drink beer, admire work.

The black box thing is where your heater core is. On the bottom there are a couple of nuts/bolts(10mm) you can remove from inside the cab. Remove/disconnect the vaccum hoses as needed.

Under the hood.
There is one bolt/nut(10mm) on top that is easy to get to beside the hoses.
Go through the hole/gap in the inner fender you made earlier and remove one more 10mm. Here comes the fun part. On top of your box where the ac lines go into it there is an electrical connector. This goes to the resistor for your blower motor. It should have 2 or 3 very small screws holding the whole thing down. Remove those and you will be able to remove the entire resistor and cover. e careful not to damage it. You will be left with a small rectangular hole that is big enough for my 3 year old to get his hand into but not me. Some dealerships/shops will remove the entire assembly that you see to get to this one freakin bolt/nut adding hours of labor. Not me, I'm all about shortcuts. Work smart not hard right? Peer into this opening (you may need a mirror) and you will see several inches down another 10mm. Thats the one you need to get out. I used a 1/4" MAC air ratchet and a 10mm wobble head socket. I had it out in 30 seconds. Dont worry about dropping it in there either since I know I'm taking the whole box out anyways.

TIP: When putting it back in if you choose too, put a piece of notebook paper about the size of a dime on top of the socket opening and force the nut/bolt into the socket. This will hold the darned thing in the socket so it wont fall out whilst you try to put it back in...if you choose to. Some people leave it out.

Once all your bolts/nuts are removed you can remove the HVAC module assembly. Its pretty self explainatory from here. Pop the top open and swap heater cores. Drink more beer, you've earned it.

Put it all back together.

I'm sure I've left some out but thats the best I can remember off the top of my head at 10 minutes past midnite. Anyone else sees anything I've omitted chime in but this should be enough to get you through it if you're halfway inclined.

Here are some pics I took of mine during the process.



The steering column
http://i259.photobucket.com/albums/h...g?t=1204693443


Two of the bolts/nut you can access from the cab. (box is upside down)
http://i259.photobucket.com/albums/h...g?t=1204693396



Another location of bolt/nut
http://i259.photobucket.com/albums/h...g?t=1204693373


Yet another
http://i259.photobucket.com/albums/h...g?t=1204693351


And another
http://i259.photobucket.com/albums/h...g?t=1204693328



Opening in fenderwell
http://i259.photobucket.com/albums/h...g?t=1204693236



Resistor removed for access to bastard bolt.
http://i259.photobucket.com/albums/h...g?t=1204693195



Time to drink beer, its out.
http://i259.photobucket.com/albums/h...g?t=1204693139



Elec connections to remove/seperate (7mm bolt)




Wires and stuff everywhere! Better have another beer.

[Kampz69]

very nice, thanks for that info and the pics! it WILL come in handy.

one thing i will add is that on blazers/jimmys etc, there is a plastic "shell" on the casing in the engine bay. to get access to the resistor, you have to actually cut the plastic. removal is the same as the S10/sonomas at that point.

[SmokeeJay]

I just did mine in my 97 S10. Was my first time. It took me about 7 hours to do by myself and I had never taken a dash apart before. I did find that I have removed more stuff than needed and if you swivel the dash forward and lift it up and out, the heater core cover is easy to get out. I paid $$35.00 for the new heater core and I was quoted over $600 for labor.

[BlackZR2MI]

My heater fan is making a lot of noise, would that be about the same I have to do to replace that?
I also need to check the vacuum lines because I have some whistling sound sometimes. And on longer drives the vents close off and I have to switch around between defrost and floor venting a couple times until I can get airflow again.

Any ideas??

[now_exowner]

I just did mine, it took about 6 hrs with no experience and some cheap labor (friend was paid in beer). I was able to separate the dash enough to get the box loosened off the wall and change the core that way. It was still a pain getting to the one bolt in the resistor hole. On the bright side, I took the overflow out, cleaned it out and completely flushed all that damned Dex-Cool out. Also was able to finally get the front edge of the dash clean. I surre hope this one liuves for a while.

Dave

[Yogi]

Excellent write-up, Dr. Evil!!

I think that I'd seriously consider selling my Blazer before I'd tackle this job though.

[Yogi]

I just sent a PM to Pewter01 to make this thread into a sticky. If you agree, send him a PM too.

[95 S_Trucker]

Quote: Originally Posted by SmokeeJay

I just did mine in my 97 S10. Was my first time. It took me about 7 hours to do by myself and I had never taken a dash apart before. I did find that I have removed more stuff than needed and if you swivel the dash forward and lift it up and out, the heater core cover is easy to get out. I paid $$35.00 for the new heater core and I was quoted over $600 for labor.

only the 94-97 can be tilted

98+ has to be removed

[onewingman]

[quote=SmokeeJay;5003934]I just did mine in my 97 S10. Was my first time. It took me about 7 hours to do by myself and I had never taken a dash apart before. I did find that I have removed more stuff than needed and if you swivel the dash forward and lift it up and out, the heater core cover is easy to get out. I paid $$35.00 for the new heater core and I was quoted over $600 for labor.[/quo
Hey, Smokee, you still around? I have a '97 JIMMY...same problem. Y mentioned you removed more than you needed to...care to elaborate? maybe save me some time and trouble. Thanks, wingman

[Rhotpursuit]

One thing I would add here is to use a generous amount of silicone just before install, around the tubes where they enter the core. The tubes are held in place by a couple of crimps and a gasket. I did this the second time after the first install failed in 6 months. No leaks and it's been several years now.

[dimedragger218]

Just did one in an 01 zr2... he was quoted twice at $800. I charged him $500 (parts included)... Plus i did two ujoints, door pins and fixed wiper linkage... When i brought it back he gave me $600 and was very happy... Dr. Evil posted the best instuctions you could get and it was exactly how i did it!
just have patients and plan your attack, and most importantly... DONT FORGET THE BEER

[CDog]

We just got the core out of 03 S10 crewcab.. F bombs everywhere!
There are just enough differences in the 03 to make you wanna kill somebody..
Example all the bolts evil says are in the cab are in the engine/fenderwall/ firewall..Argggh! we will post pics later to add to evils great slideshow!

[ericknight]

I just put a heater core in a 2000 Blazer yesterday, it took me about 7 hours. I didn't have any trouble with the bolt in the AC box, but the one directly behind the RH manifold was hard to get to. I took the inner fender out, and the 3 nuts/clips directly under the battery broke, but I was able to get replacements at Auto Zone. Here's some more info I found for anyone else who will be replacing theirs.

http://www.s-10crewcab.com/phpBB2/viewtopic.php?t=3579

and some pics I found which were useful.

http://s395.photobucket.com/albums/p...20Replacement/

[FK-IT]

ok now you do have to take the instrumentpanel out theres two 7mm bolts holding the dash in. But other than that me and my buddy had mine out in a hour just one person on each side. i just hope all this can go back in easy.

[FK-IT]

Well yes i agree theres a few aggrivations but 4 bolts under the hood and a few on the inside. your good you only need it out far enough to get the old core out and it took me all in all about 3 hours kinda made me feel like i did something great with nothing to show for it.

[Yogi]

Quote: Originally Posted by FK-IT

Well yes i agree theres a few aggrivations but 4 bolts under the hood and a few on the inside. your good you only need it out far enough to get the old core out and it took me all in all about 3 hours kinda made me feel like i did something great with nothing to show for it.

So, you didn't take the instrument panel all the way out or what?
How did you do it so fast?

[FK-IT]

i really don't know.. its not hard at all just take your glovebox out. then the front face of the dash. take your panel out. theres two bolts behind there. theres bolts in the coners of your dash. take your speaker covers off the top and pop off the middle vent undo those screws. drop your steering colum and start unpluggin anything thats caught. and then under the hood- if you take the passenger front tire off and jack it up its easy but through the flap on the firewall theres a bolt then 3 others up top and your good. THE THING IS YOU DON'T HAVE TO TAKE IT ALL THE WAY OUT. JUST GET IT LOOSE AND TILT IT TO GET THE CORE OUT AND THE NEW ONE IT..

[monette999]

How about a heater core replacement of an 1997 Blazer.

See my pictures I posted.
Same procedure or little bit easier?

http://www.s10forum.com/forum/f136/h...6/#post6056838

bob

[Merritt]

After reading this how to I can see why I've been riding without heat for the past 2 winters. I can't justify spending that kind of money, and I'm too lazy to do it myself. The dealership quoted me at $1400, can you believe it? Local garage quoted me at $800, a little better, but I'll be damned if I'm gonna pay that much, I'll put a damn woodstove in the extended cab and run a chimney through the roof before I give somebody $1400 to fix my heat.

[Dr Evil]

Quote: Originally Posted by Merritj2417

After reading this how to I can see why I've been riding without heat for the past 2 winters. I can't justify spending that kind of money, and I'm too lazy to do it myself. The dealership quoted me at $1400, can you believe it? Local garage quoted me at $800, a little better, but I'll be damned if I'm gonna pay that much, I'll put a damn woodstove in the extended cab and run a chimney through the roof before I give somebody $1400 to fix my heat.

I was gonna say if you are close to knoxville just bring it over one day and we'll knock it out but you're easily 4 hours away.

[Merritt]

Quote: Originally Posted by Dr Evil

I was gonna say if you are close to knoxville just bring it over one day and we'll knock it out but you're easily 4 hours away.

I'll be there in a minute.

[FK-IT]

no but serioulsy mrrit i live in archdale nc nd can do it for u in a day easy nd alot cheaper than 800.00

[lwrd93]

anyone wana come to tx and do this for me?? i got a case of beer for ya

[Aso]

How do you remove the inner fender, why do you have to remove the battery i did both and the fender still seems attached?

[Merritt]

Me and sockjock replaced mine finally. It didn't take us long, just 13 hours, lol. When GM made the '03 S10 they didn't want you to be able to take it apart, that's for sure. There were nuts and bolts in all kinds of tight spaces, but we finally got it done and now the heat works!

[gixxer32404]

This makes me want to cry....LOL. I recently bought a 96 s10. Previousowner had it disconnected. He said in Florida you didn't need heat. It sucks not having defrost during rain. I was quoted 400-600. part under $80.00.

[kab1822]

thats intense

[992drjimmy]

Somebody want to . come and give me a hand on my 96 Im in decatur IN

[navybrat02]

Mine went out in my 2000... I'm just going to connect the inlet and outlet and by pass the heater core all in itself...

[lwrd93]

thats what im gona do as well navybrat

[xtremewhite99]

when your heater core is gone do you still have heat coming thru the vents.

[white01extcab]

woooohoooo! thank for the info guys. sounds easy enough. and cheap.

[zr2bccan]

Be careful bi-passing the heater core. On mine the inlet is a different size than the output. Wouldn't want to have it pop in the bush.

[retro]

It took a few hours but it wasnt that bad... and im a girl. lol

[andyswmr714]

Dr. Evil Your write up is amazing.

[Xtreme1999]

Write up was good and helped a lot. Didn’t put the bolt back in near AC coil.
Did mine this weekend on a 99 X. Took me about 4 hours to get everything unhooked and ready to go back together, would have been shorter but had back surgery 3 weeks earlier so I took it easy. About an hour to put back together.
Anyways, I made sure I clipped in the air bag plugs and put the little orange clips back in but my air bag light is still on. I have driven it about 200 miles since but hasn’t gone out. Any way to reset?
JT