Heater core blew up a couple of years ago

I have a new one but have been afraid to let anyone do the work,
because I tend to find the most incompetent mechanics on the planet.

I live in Fl so AC is more important to me than heat, and I'm afraid they will hurt my working AC

Here’s my question…Do they have to mess with AC components, like evaporator when replacing the heater core?

A local mechanic told me he wouldn’t know until he got into it and he would charge either $170.00 or $240.00 depending on what components he would have to move.

Sorry, but I don’t like that answer. I want to know ahead of time.

What say ye? I could tough it out and go without again, but I work nights and it would be nice to have a little heat.

Heater core blew up a couple of years ago

I have a new one but have been afraid to let anyone do the work,
because I tend to find the most incompetent mechanics on the planet.

I live in Fl so AC is more important to me than heat, and I'm afraid they will hurt my working AC

Here’s my question…Do they have to mess with AC components, like evaporator when replacing the heater core?

A local mechanic told me he wouldn’t know until he got into it and he would charge either $170.00 or $240.00 depending on what components he would have to move.

Sorry, but I don’t like that answer. I want to know ahead of time.

What say ye? I could tough it out and go without again, but I work nights and it would be nice to have a little heat.



I've had to replace the heater cores in just about all my 6.2 diesel trucks. I've got over 20, so I must assume GM made some pretty crappy cores. With my two 83 K5s, an 86 K5, and 87 Suburban - they all have AC. I can't remember all the details -but I can tell you this for sure. It took between one and two hours, and none of the AC lines had to be unhooked. So, no R12 or 134A lost, no evacuating, recharging, etc. I've also had to remove the cores - not to replace, but to remove mouse nests. Mice love to rip the sound-insulation out of the hood, and bring it into the heater-core for a winter home.
Biggest problem - is the plastic-insulation covering on the heater/evaporator box that you see when you open the hood. To remove it in one piece is very time consuming. I cut mine and pieced it back together. It does not look as pretty that way, but does not effect performance of the heater or AC. It's just a thin layer of plastic -but if you insist on it coming off in one piece, it will add a lot of time to the job.
In regard to incompetence - it exists in any job field. Don't have a good answer for that - except, when in doubt - do it yourself. In regard to me cutting off the plastic - these are my vehicles. If it was someone elses - I'd ask first - and explain the labor-costs involved in doing it either way.

The air conditioning shouldn't need to be removed to change the heater core. That shouldn't be an issue.

GM heater cores are rather bad, but they usually fail when someone forgets to change the coolant and flush the system on a regular basis. If it is done regularly the heater cores last much longer. Fortunately, GM heater cores are also fairly easy to change (as heater cores go), so changing them every now and then isn't that big of a deal.

$200 for a heater core change is pretty cheap... In my area, most mechanics charge about $350. Of course, the heater core is actually only a $45 part...

The air conditioning shouldn't need to be removed to change the heater core. That shouldn't be an issue.

GM heater cores are rather bad, but they usually fail when someone forgets to change the coolant and flush the system on a regular basis. If it is done regularly the heater cores last much longer. Fortunately, GM heater cores are also fairly easy to change (as heater cores go), so changing tham every now and then isn't that big of a deal.

$200 for a heater core change is pretty cheap... In my area, most mechanics charge about $350. Of course, the heater core is actually only a $45 part...

I can't comment on labor rates in your area - or labor quality. But, I've run my own shop in a rural area of New York for over 30 years. I no longer work on registered autos -for many reasons. Main reason is all the licensing and state fees involved. So, now - I repair mosty off-road diesel equipment and antique or collector's cars, tractors, and boats. I also help out a friend who runs and owns a basically "one man" auto repair business. He's been at it for 40 years, and before that his dad ran it for over 40 years. He's just about had it though, with all the fees, taxes, equipment costs, etc. Regardless, his current labor rate is $55 per hour, and he would change that core for no more than $100 plus cost of materials (parts, hoses, coolant, etc.). If I were doing it, it would be the same. Now, the local Chevy dealer charges somewhere around $100 per hour - and who knows how long they would have to jerk around with what they consider an "antique."
In regard to core quality - I make my comments on a relative scale. MY 1969 W200 Dodge Powerwagon still has its original heater core - and it's been a plow truck for past ten years with NO coolant or oil changes. If it blows up tomorrow, I don't really care. Also, my 69 MGB, 79 Datsun 280ZX, several early 80s Subarus, 85 and 94 Ford F250 diesels all have their original heater cores. My GMs? Just about every one of them has had a bad core - and my 95 Chevy Astrovan has had two in 140,000 miles. Only GMs that haven't gone bad are my two diesel Chevettes and my 65 Chevelle SS. I will also add that all my diesels are highly maintained along with PH checking the coolant every year. From my experience with those vehicles, and my reference frame, the GM cores are CRAP.

Thanks guys for the wonderful advice
As they say, forewarned is forearmed

It is good to know about the plastic cover on the evaporator

Maybe I can negotiate the cost if it won’t take as long( piecing
the cover back)

So I guess you guys are absolutely positive that the mechanic

should in no way have to disconnect any AC hoses.

That makes me happy!

its a seperate system other than the fan/vents (depending on the model you have, pretty sure that your year truck its entirely seperate). you have nothing to worry about with your ac system. are you replacing both your front/rear heater cores?

Just to clarify a little more on heater core replacement: There are about 4 or 5 nuts on the firewall side that attach to studs from the inner heater housing. Heater hoses need to be removed along with these nuts and the plastic shield, the glove box needs to be removed and some of the vacuum lines disconnected along with the defroster duct. Then the inner housing can be removed from truck and disassembled to get at the heater core. Hope this gives you a better idea. Find a shop that charges on flat rate, that way you only pay for the alotted time and not actual time. I get to replace one on turkey day for my daughter as hers is leaking again(replacements aren't all that great)

not sure on the labor time..i havent touched one of these in a long time.
but, to help keep your heater cores from going to the crapper so often, while replacing the core, solder a small gauge wire to the heater core and run the wire to a good body ground. 90% of "corrosion" and heater core failure is caused by electrolysis.
Connect the negative terminal of a voltmeter to the chassis ground. Test for adequate continuity by touching another point on the chassis - the resistance should be near to zero. With the engine cold and running, submerge the positive probe into the coolant tank, making sure that the probe does not touch any metal parts. The voltage should be less than .10 volts, if not, flush your coolant and add a ground to your core, or....find the poor or lost ground in your elecrical system.(which can be ungodly time consuming)

Replaced mine in January on an '87. Basically I helped:rolleyes:

I can't remember why but we did disconnect and pull the Dryer (large silver aluminum thing). Considered pulling the fender well for better access. One nut is really badCensored The core itself is pulled through the cab.

It's an easy job if you don't have AC:mad::mad:

I remember, we pulled the Dryer so we didn't have to cut the plastic.

I have heard most cut the plastic. Probably saves half the time:confused:

out of two 84's one 85 and an 87 all with ac and they don't get alot of miles on them and all are on the original heater cores.

6.2gal, I am in the panhandle...
If you help me get ol'blue runnin' ie:crankin her or a here hold this etc... I will put yer core in fer free!
I do take bit longer but just cuz I ain't in a hurry and tend to look at it like a family bar-b-que! if I take a bit longer we have better steak!
Brent!

Follow DCam's instructions. Add this, remove the rf tire and the inner fender panel (splash shield). I know, PITA but it allows access to all the nuts on the heater housing studs. Also gives room to remove the sound insulator with more room to reassemble it if you cut if up. It's not complicated, just time consuming. Also allows room to replace heater hoses without bending/kinking the new heater core hose fittings. Be careful, I've seen them leak after much tweaking.

I've had to replace the heater cores in just about all my 6.2 diesel trucks. I've got over 20, so I must assume GM made some pretty crappy cores. With my two 83 K5s, an 86 K5, and 87 Suburban - they all have AC. I can't remember all the details -but I can tell you this for sure. It took between one and two hours, and none of the AC lines had to be unhooked. So, no R12 or 134A lost, no evacuating, recharging, etc. I've also had to remove the cores - not to replace, but to remove mouse nests. Mice love to rip the sound-insulation out of the hood, and bring it into the heater-core for a winter home.
Biggest problem - is the plastic-insulation covering on the heater/evaporator box that you see when you open the hood. To remove it in one piece is very time consuming. I cut mine and pieced it back together. It does not look as pretty that way, but does not effect performance of the heater or AC. It's just a thin layer of plastic -but if you insist on it coming off in one piece, it will add a lot of time to the job.
In regard to incompetence - it exists in any job field. Don't have a good answer for that - except, when in doubt - do it yourself. In regard to me cutting off the plastic - these are my vehicles. If it was someone elses - I'd ask first - and explain the labor-costs involved in doing it either way.

the reason you have so much trouble with your heater cores is they don't get used!!:D over 20 trucks!!:eek:

Hey Hotdogs, Thanks for the offer to help. I love you for it.

If I had some time off from work, I would drive up there in a flash,

but alas it is not possible this month.

Now I have to put this repair off and take care of a new, more important one,

which I will post about.

This isn't all that hard, but like Fred 482 said, remove inner fender for ease. I prompted my daughter Laura to replace her own, I lended tech support (I watched and assisted when needed) She did 85% of the job:D I will rate this as about a 3 hour project. I would also suggest removing the sound insulation from the outside of the a/c evaporator and throw it away! It doesn't add that much insulation, but it sure adds a lot of time to the job.

This isn't all that hard, but like Fred 482 said, remove inner fender for ease. I prompted my daughter Laura to replace her own, I lended tech support (I watched and assisted when needed) She did 85% of the job:D I will rate this as about a 3 hour project. I would also suggest removing the sound insulation from the outside of the a/c evaporator and throw it away! It doesn't add that much insulation, but it sure adds a lot of time to the job.

In most cases, removing the inner-fender is not practical - not in my area. Vehicles are usually too rusty, and you cannot remove the inner fender without doing a lot of damage. The heater core can be easily changed without such removal, I've done many.