1990 heater core replacement

'90 annyedition

Registered User
Hey guys. I have ordered a new heater core for my 1990 supercoupe and just wondering if anyone out there has had any experience replacing one of these?
I know the entire dash needs to be removed. There doesn’t seem to be any video on YouTube. I have it with my mechanic who is an older guy and he cannot even locate the heater hoses, any helpful information would be greatly appreciated. Thank you.
 

DOUG H

SCCoA Member
If he can't even locate the heater hoses, find a different mechanic would be my suggestion.

Other suggestion, replace A/C evaporator while you have it all out.

Older guy, a 33 old car would be when he should've been in his prime.
 

351tt

Registered User
" if he can't even locate the heater hoses, find a different mechanic " x 10
You may eventually have to fix what he did not know about .
Pulling a dash is a big job , so one mistake means two big jobs .
Back yard mid level mechanics can do it with fairly basic tools , I have pulled more than a few , not that hard with two people and taking notes/pictures [ lots of pictures ] , its putting them back in correctly is the trick... the bolts/screws if taken out and recorded where they go back is the easy part, the wiring meaning connectors etc along with the air conditioning controls and vac lines that needs to be disconnected and reconnected in the proper order is what needs the most attention.
Pull the front seats, pull the steering column and console first if you are going to attempt it .
Just a guess from memory which is not that good, probably a two + hours to pull the dash out and probably four+ hours from that point to put it all back in ..those water hoses are probably going to be a biatch to get at to take them off... the work in the car will be much easier in comparison to under the hood .
The reason for all this is it is hard to find people/mechanics that know these cars so you may be better off taking a shot at it [ with some help ] yourself.
 

DOUG H

SCCoA Member
If I recall correctly, I think my 1st was 3 hours to dissasemble & 4 to put back together & the 2nd was 2 hours apart & 2 hours to put back together. I remembered a few tricks/shortcuts from 1st time I guess.

2nd time I forgot to connect a ground on the C.D. player, so nothing worked( radio or C.D.) easy fix.
 

35th

Registered User
The heater hoses are definitely a Pita one hose comes from the driver side other comes from pass side although the both end up on passenger side the go through the firewall near the ac dryer. So if looking at the dryer look further down towards the ground and towards the center of the car it's easier to get to if you take off the wipers and the cowl (careful with the cowl it's pretty brittle) and also the support bracket that thr cowl screws to. While your in there take a look at the fresh air vent make sure thr seal is good (they can leak and water ends up on your computer inside the dash) repair as needed
 

'90 annyedition

Registered User
Thank you guys so much for all the useful information. It is greatly appreciated!
I knew it was going to be a big job but now it’s sounding like a HUGE job.
My mechanic shop quoted me 9 hours at $135/hr so they gave me the old guy mechanic’s number but I might have to take it back to the shop and pay a fortune to have them do it.
Again, thank you guys
 

351tt

Registered User
Thank you guys so much for all the useful information. It is greatly appreciated!
I knew it was going to be a big job but now it’s sounding like a HUGE job.
My mechanic shop quoted me 9 hours at $135/hr so they gave me the old guy mechanic’s number but I might have to take it back to the shop and pay a fortune to have them do it.
Again, thank you guys
1200+ is nuts , yes it is a big job but not brain surgery , unless you are rolling in the cash and don't care about paying that , I suggest getting a friend or two that have some mechanical experience and take a run at it , you have enough info here to know what to look for and avoid ..you should be able to get it done in a day, early start, no beer till finished .
 

DOUG H

SCCoA Member
9 hours sounds a little excessive, 4-5 would be more in line for a "professional"shop.

I think I've got a 1993 flat rate manual at home, I'll check tonight.
 

DOUG H

SCCoA Member
Evacuate & recharge A/C if equipped 1.4hrs.
Heater core renew 89-93 Thunderbird/Cougar 4.5hrs.-includes coolant drain, refill & purge.
Autotemp control add .5hrs
Cooling system service(flush/renew) add .7hrs
 

SC-AL

SCCoA Member
Remove & Replace Heater Core DOES NOT include Air Conditioning System recover, evacuate and/or recharge.NOTE 1: Estimates shown DO NOT include recover, evacuate, and recharge. 8.6hr.
This from a more recent labor guide. My older labor guide shows 4.5hr, (which is a factory warranty time). The adjusted actual time was 7.5hr. Theses times also doesn't include A/C recover, and recharge. Remember, these times assume experienced professional,(that has probably done 4-5 of this model), and everything goes smoothly.
 

DOUG H

SCCoA Member
The other thing to remember is these times were based on a 5-8 year old car when published, not something that's 33 years old with rusted bolt's/studs, brittle plastic retainer clips, stiff hoses/lines, etc. Maybe 9 hours isn't that far off when you take that into consideration. I meant to put that in my 1st labor response. My labour guide book advises to add 1.4 hrs for A/C equipped cars for evacuate/recharge to the basic 4.5hrs.
 

SC-AL

SCCoA Member
My labor guide book advises to add 1.4 hrs for A/C equipped cars for evacuate/recharge to the basic 4.5hrs.

But again, your Labor guide is showing 4.5hrs. This is only what the factory will allow for warranty repairs. It is why mitchell, alldata, and chilton professional labor guides always have the adjusted real world numbers. And you are right about brittle plastic, and corroded fasteners, etc.

I always "beat the book" on the 1.4 Recover/recharge time, though. This is what insurance companies paid body shops.
 

AdamG

SCCoA Member
The last time I changed my heater core about a year ago it took me about 4 hours. I didn't have to evacuate the a/c, only removed the dash far enough to sneak the core out of the slot. Remove center console, then carefully ( I do mean carefully) remove the trim piece between the cluster and windshield, there are 2 8mm bolts to remove, then remove the trim piece on the passenger side of the dash (once again, very carefully, those clips are super brittle), that will expose 2 more 8mm bolts. Remove the glove box and you can then access 2 10mm bolts under the dash next to the door. Remove lower trim under the steering wheel. 3 more 10mm bolts, 2 by door, 1 by fusebox. 2 11mm nuts in the center at the bottom by where the center console meets the dash. Remove 4 13mm nuts off the steering wheel where it mounts, slide the steering wheel down and then the dash should be free. You can work on sliding the dash back, a few wire harness connections will need to be separated by the computer on the passenger side. You will see a cover with 2 8mm bolts that covers the core. After the heater hoses are disconnected it should slide out. Now to get it back in, an extra set of hands helps. Since the tubes angle away from each other, there is a rubber seal by the firewall they don't like to go back through. If you take some smaller hose, stick those through the holes from the engine side of the firewall. Then insert those in the heater core tubes and use those as guides to slide it back in. You can do it without those hoses, that's just a suggestion to get through that seal. I did it without them and by myself and still got it with a little fighting back and forth and swearing. Once through the seal, just reassemble the rest. Hope this helps...
 
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