1990 Custom Cruiser blown heater core

It's easy. The real trick will be finding one in stock for the weekend.

You need a couple 1/4" sockets, a 7mm, 10mm and a 5.5mm, I think. Drop the underdash cover on the passenger side if there is one and remove the glovebox door, if it's in the way. Take the 5 or 6 tiny screws out of the bottom of the heater box. A short extension and a wobble will help you here. The two up near the firewall are a total PITA to get to (you may leave one or two out on reassembly ). I think there's a couple 10mm bolts that hold the HC bracket in place. Remove the hoses underhood at the heater core. Remove heater core. I may have left one or two steps out, but that should get you pretty close...

Install is reverse of directions.

Good luck.

toomanytoyz wrote:

It's easy. The real trick will be finding one in stock for the weekend.

You need a couple 1/4" sockets, a 7mm, 10mm and a 5.5mm, I think. Drop the underdash cover on the passenger side if there is one and remove the glovebox door, if it's in the way. Take the 5 or 6 tiny screws out of the bottom of the heater box. A short extension and a wobble will help you here. The two up near the firewall are a total PITA to get to (you may leave one or two out on reassembly ). I think there's a couple 10mm bolts that hold the HC bracket in place. Remove the hoses underhood at the heater core. Remove heater core. I may have left one or two steps out, but that should get you pretty close...

Install is reverse of directions.

Good luck.

So it's pretty much the same as my '96 RMW then. I guess. Anyway it sounds easy. Thanks. I was afraid the '90 would be different and from before they figured out people want to replace those.

On the 90, it's under the hood on the fire wall, even easier than the 91-96

Well there you go then. I missed that it was a boxy.

Not that this matters in this case but the TBI wagons use a 6mm on the bottom of "the tray"
and the LT1 wagons are 5.5.....or was it the other way round? In any event you get the idea.

This is for the 77-90 B-Body full-size cars.

Its actually pretty easy. The heater core is located under the hood, passenger side.

Disconnect the two heater hoses running into the firewall. Remove the leaf guard then start pulling bolts on the black housing. (remember where they go of course, I had 3 different sizes on mine to boot!)

You will need to disconnect the wiring harness on the top pf the housing and remove the blower fan before removing the housing.

Once you have undone about 25 bolts you can remove the housing. You will see your AC Evaporator and your heater core. (In my Caprice the heater core was the one closer to the middle of the firewall)

The heater core should just slide out of its little home, replace it and you can then put it all back together in reverse order.

Hope that gets you there!

-Mike

81X11 wrote:

This is for the 77-90 B-Body full-size cars.

Its actually pretty easy. The heater core is located under the hood, passenger side.

Disconnect the two heater hoses running into the firewall. Remove the leaf guard then start pulling bolts on the black housing. (remember where they go of course, I had 3 different sizes on mine to boot!)

You will need to disconnect the wiring harness on the top pf the housing and remove the blower fan before removing the housing.

Once you have undone about 25 bolts you can remove the housing. You will see your AC Evaporator and your heater core. (In my Caprice the heater core was the one closer to the middle of the firewall)

The heater core should just slide out of its little home, replace it and you can then put it all back together in reverse order.

Hope that gets you there!

-Mike

Thanks. That's exactly what I wanted. I was a little concerned about the AC and how it might impact things. I haven't even peeked under the hood on this car yet. I'll probably pull the hoses off the core before we head out to the Autozone which says they stock the heater core at all their stores. Mabye I'll even call them first. :-)

Okay, we're getting into this thing. Getting that top piece of plastic off wasn't trivial because someone had glued it along the firewall with hot tar that's now quite hard in the cool air. Then I thought just the top came off until I saw I had to undo parts of the inner box to come out with it. I'm thinking an exploded diagram would have been handy.

NOW though we have the core fully exposed and have removed the hoses and upper clamp but it won't come out. It rocks and pivots but won't pull up. What am I missing? We're gonna roll out and buy the new one to see if there's a threaded fitting on the bottom or it looks like a snap clip of some sort is holding it down. Dang this thing is harder than I expected.

Some of those screws at odd angles and bad places are tough to get out. Lining them up to go back in is not going to be a picnic.

Add to that he's now thinking he should sell this car to get a minivan. This thing is immaculate! Shoot.

sawzall makes it quicker,.

good opportunity for you to gain a wagon,.

Send me pics if he puts it up for sale. I MISS my '89 Custom Cruiser A LOT.

That black tacky tar-tape is a messy nightmare.

Hope you got it back together!

-Mike

Now now Mike... remember we had this talk? Another car, hell, another WAGON is sure to turn you into the next John Bobbitt.

81X11 wrote:

Send me pics if he puts it up for sale. I MISS my '89 Custom Cruiser A LOT.

That black tacky tar-tape is a messy nightmare.

Hope you got it back together!

-Mike

This was NOT tape. Someone had poured a hot sticky tar mix along the seam. It had run down in spots and globs then was squashed out by putting the leaf guard back onto it while hot. I know it did the job though.

We got it back together after some dancing with the clip at the bottom of the core and it works beautifully. I screwed up and split the thread on the pressure sensor attached to the accumulator when I was putting that back on so he'll be buying a new one of those soon. He's got the car loaded with stuff from his MIL's house that they're taking to WV with them but I can take pictures of the car with that in there. They're pretty sure they want to get a minivan now so this would be the time. He's owned it since '93 and kept it either in a garage or in a carport. I can't believe the shape of the paint and the wood grain.