I've read the tech article concerning replacing a heater core and have also read previous horror stories about changing them... well, my turn has finally come. It's a pretty straight-forward article, but I would like to know if there are any "helpful hints" out there to assist in the operation. I'm not sure when mine started leaking, car hadn't been driven for a couple of weeks and when I was vacuuming it out yesterday and removed the floormats, that is when I found the nice wet carpet on the passenger side. Didn't smell like anti-freeze, but when I pulled the carpet away from the firewall, I could see a little green/brown trail. Water level looked OK, so once again, I don't know when it started.

Also, does the core leak only if the heat is on and warm, or can it leak at any time?

Another question, is it possible for a core to get blocked by leaves and other debris? (I don't know if the air flows over it all the time or not) Reason I ask is because my airflow to all vents seems to be lacking. If I have the fan on high, it seems like it's only medium, no matter if heat, a/c, or defrost, etc.

Thanks for any and all help...

KAM

 

core can leak anytime

it should take about 2-3 hours

remove dash pad ( lots of screws )
remove lower panel from passenger side
remove speaker
there are 2 bolts on each side of the dash board, once the pad is off you can remove the right ones and loosen the left ones.

drain the AF , remove the heater hoses

there is a box above the kick panel it has about 6 screws around its perimeter, remove them. one or two aren't visible but you can feel for them and remove them ( 7mm i believe). pull the dash away and pull that cover out. the HC will be visible and almost fall out.

be sure to replace with a new one they are cheap, leak check if you can BEFORE you install it.

 

Mine took about 45 mins or so. Didn't have to touch the dash, just look under the pass side dash first to see if you see a small black panel...

 

I think it depends on what year car you have. The 91's and 92's are a little more involved. Dash pad will have to come off. Mid to late 80's will have an easier time. Some of the guys reported just having to remove the kick pad under the passenger side dash.

 

My '86 TA core went out and in within 45 minutes, without touching the dash pad. To access the uppermost screw on the core case, remove the large hex head screw on the lower right corner of the dash, then flex the dash panel outward just slightly to enable a ratchet, extensions, and 7mm socket up to the top screw. Removing the top dash cove isn't that difficult either, so it's your call.

The best advice I can give is to match the old core to the replacement by comparing the outlet tubes. The angles must match exactly, or you won't get the heater hoses back on the pipes. There is very little room to work with the hoses behind the right head, so the pipe angles are crucial.

 

Yup, no matter how close they look, if not exact, you won't be able to bend them enough, darn Trak Auto..

 

Yea, removing the dashpad is easy enough to do this, and yes, it's a '91... so maybe a little more difficult? No big deal. Thanks for the heads up on the "exact tube" thing. I was going to go get one and do the swap all at the same time, but I think I'll remove the old one and take it with me to match up. Thanks for the help, guys...

Any thoughts on the "lack of airflow" issue?

KAM

 

These cars have a somewhat weak blower to begin with. But, the first thing the air hits on its way into the car, is the A/C evaporator. This has a screen on the front side of it to catch leaves and stuff and can easily get stopped up. You can take off the top of the evap housing quite easily, about 12 or 15 7mm screws and a couple of other little things, and clean it off.

 

when i did mine i had no idea where the screws would be so i took the pad off ( 84) but on secont thought if you really have faith in this boared you may be able to do it without taking the dash pad off or loosening the dash, it just makes it easier

 

T-Tops off helps!

Being cursed with meathooks instead of hands I took the whole dash off, then unbolted the .........what's it called, where the glove box would be if one existed, and slid it out. Then, for headroom to help reach stuff from the top I took the passenger side T Top off.

 

Well thanks for all the inputs guys... got it done today... (started a couple of days ago, but got distracted doing other things plus having to make use of the decent weather for yard work and car washing...) I did have to remove the dash pad, but when I put it all back together I left that top screw out since it didn't serve much more of a purpose than to cause a big pain in my ***. The cover interlocks in place and the other 3 screws on it suffice just fine. I ended up replacing the heater hoses and oil cooler hoses since those didn't get replaced when I did the rest. Anyhow, it's all back together now, leaks checks were good, heats up good, even got a better airflow, so maybe the old one was kinda clogged??? I tried to take the a/c evap cover off, but it didn't want to clear the accumulator and I could see in there good enough to see there was no debris. Other than that, just waiting for the carpet to dry out so I can put it back in place but at least I can drive it now!!!

 

Glad to hear you got it finished.

I got mine out, but haven't put it back in yet.

Distractions!

 

T-Stick,

That carpet probably won't dry out unless you were using nothing but water in your cooling system. All the water will evaporate, but will leave behind the concentrated coolant.

The best thing I've found is to use hot water to thin the coolant, then suck up the mixture with a wet/dry vac. Repeat this procedure several times to get all the coolant out of the carpet fibers, then blot the area dry with a towel and turn on the heat to dry it up completely. If the carpet still feels tacky, do it all over again until the coolant is gone.