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Has anyone on here replaced a heater core in their Legacy?

It's time to do mine.

Yesturday on the way home from work- the car in front of me must have had a bad head gasket or cracked head or something because I could smell a little antifeeze.

On the way to work tonight- a different car in front of me had the same issue, but a stronger antifreeze smell. Only this time, the other car somehow caused my windshield to become very foggy. I had to keep a napkin in one hand it was so bad. (Cold and rainy in Portland, OR).

So I guess the timing is right since there is a spare sitting in the parts car in my driveway.

I'm just wondering if there is anything weird to the replacement of a heater core in a Subaru Legacy. I need to replace the A/C evaprator as well, but I think they are in different housings under the dash.

yes they are in different housings. I don't know if there's anything weird about replacing it.....other than the dash has to come out....

Fairly straight forward, once you find all the various hiding places for the screws. Just a major pain in the ass removing the whole dash. Some say you have remove the core w/o discharging the A/C -- I didn't find this true in my '94 TW.

This looks like a real PITA job.

Luckily, I guess, the A/C core needs replaced too (or just o-ring). It's an R12 system

I'll be doing the conversion to R134a

For anyone else needing to do this - Its a SERIOUS pain in the ass to do this without cracking open the AC but its possible. My 91 Legacy has gone through two heater core replacements and three engine removals without opening the AC which still has the original R12 from Indiana

The job is done. And it sucked.

I replaced the heater and a/c, both were leaking. Now on to the r12 to r134a mod...

Now the replacement heater core is leaking! This is not a job I wanted to do twice!

Does anyone know what could be causing this?

Both times, there was no liquid dripping inside the car or outside. It just smells like antifreeze when I turn the heater lever to the red side. The windshield also steams up. There doesn't seem to be any coolant loss in the system after a month of driving it like this. I wonder if there is a leak that is only leaking when the engine is hot and high RPM?

I'm not looking forward to doing this job again and I don't want to put alumaseal in there. Any ideas?

You're going through the same shit as I did a few years ago with my 90 L wagon. I think I had my dash out and back in again 3 times before it was over with. I hate removing the dash. I bought a new one because there was no way I was going to go through all that and then have it leak again when I was done.

maybe theres a leak in the line its self, i had a van that i replaced the core only to find out that there was a crack in the line right at the firewall and it was driping into the core box

I think I'll bypass the heater core and pressure test the core in-place. I will pressure test the one I pulled out a few months ago before tearing my dash apart again. The problem went away with the replacement so I'm pretty sure the core is cracked. I can't help but wonder if my coolant system was just operating with the wrong cap or something and maybe the pressure was gong too high??? I replaced the cap with a 14psi one. I suppose I should verify everything before I tear into it again.

It's such a strange failure since I never see coolant dripping from anywhere. No wet carpet, nothing. Just a steamy windshield and the nasty smell when I slide the temp lever to the red side.

Does anyone know if the replacement core is any different than the original one? Until what year did they use that part?

The leak was where the core tubes meet the cans.

For a temporary solution, I plumbed the leaking heater core into the intercooler plumbing. It blows just warm enough to defog my windshield. Intake temps are WAY down now though! haha!

The intercooler plumbing is pretty much at 0psi so no leak. I'm using PROPYLENE glycol so no nasty toxic fumes if it does leak.

I think I'll pick up a heated seat cover to get me through the winter...

When I first read that post I thought you had plumbed in your heater core inline with your regular air cooled TMIC! Haha. I was like...wtf?!

My sister has my old car that I replaced the heater core with a brand new heater core from subaru for like $130 about 3 years ago and it just leaking again! One of her friends bypassed the heater core for her but that's a shitty solution when you live in washington where it's cold and rainy 3/4 of the year.

What do you mean by "where the core meets the cans"? I'm not pulling her dash out unless she buys another brand new heater core and she doesn't have money so I doubt that will happen.

I plumbed the leaking heater core into the intercooler plumbing. It blows just warm enough to defog my windshield. Intake temps are WAY down now though! haha!

I am also replacing my heater core and I finally have the dash out! However I can't seem to find a way to remove the heater box to get to the core. I have tried the search option but I haven't found anything on how to do it. With having limited mechanical skills and have never done this before I had to walk away from it for a while. This is my first Subaru but I have to say they are really easy to work on. Just wish there was more youtube videos on how to do things on the 90-94 legacys. Any info would be much appreciated.

Did you remove the heater hoses from the heater core in the engine bay?

yes I have both hoses off I just can't figure out how to remove the heater box to get to the core.

Isnt there a nut or two underneath?

You will need to loosen the AC box and pull it out a little for the heater box to come out. No need to remove the A/C box.

I was finally able to do it. I wasn't able to pull it out due to the brace that is attached to the steering wheel. Once that was out it just came straight out. I was glad that I didn't have to discharge the AC. However I wasn't too happy with the new heater I got from autozone. It did not come with the tubes and gaskets. I didn't mind reusing the tubes but I didn't feel ok reusing the gaskets. I tried searching different auto part stores but no one had something similar. If it fails then it will stay broke for a long time because I don't plan on doing this again any time soon. It was a pain in the butt however I saved myself 350 dollars in labor.

Those gaskets are very brittle, I put a little ultra black on mine to make sure it was sealed. There's no part # for that gasket at Subaru, it come with the heater core. Aftermarket heater cores are universal, I believe that core also fits a Nissan,Subaru,Frounter and Xterra's from 89-04.

Just for others doing this sorta stuff, most always special seals or orings or gaskets, try your dealer parts department first.