1973olds98

i finally got my newly rebuilt 455 started,,,,Everything seemed good until i notice coolant inside the car...I assume the heater core went bad,,,,,Does anyone have a clue on how to remove the heater core....thanks

MDchanic

Sure it's not just a poorly attached or tightened heater hose?
They're tight up against that hole through the firewall, and if they leak, it will often all go inside.

- Eric

jaunty75

Yes, but before I tell the story, my first question is, why haven't you yet purchased service manuals for this car? They're indispensable for the things you're doing and will want to do!


Instructions from page 1-5 of the 1973 Olds Chassis Service Manual:

1. Disconnect battery.
2. Remove four heater case attaching nuts to dash panel. (The heater case is under the dash on the right side, and removing the lower right side dash panel and glovebox will make access much easier.)
3. Drain radiator below heater level, disconnect heater hoses.
4. Disconnect temperature cable, defroster cable, and vacuum hose from heater case.
5. Remove defroster duct to case attaching screw.
6. Disconnect right half of right hand trim panel.
7. Remove heater case from inside car.
8. Remove heater core from case.

To install, reverse removal procedure.

1973olds98

I check the hoses and its not leaking from them....I do have the chassis manual for this car,,,but instructions dont seem clear..

jaunty75

Are you looking at the same manual I am? Do you see the same steps as I've listed above on page 1-5? If you have the manual, you can also see the figures and diagrams that go with them. I don't really see how they're not clear.

It's a general fact of life that heater core removal is usually a pain the ***. It involves getting up under the dash in places that are uncomfortable to reach, and one often has to significantly disassemble the dash to get at it.

Sometimes it involves removing the right front wheel or drilling holes through inner fenders to reach an attaching nut. Fortunately, those are not necessary here.

As heater core removal projects go, and while I've not actually done it myself on my '73 (and I hope I never have to), it sounds and looks like this one is a relatively easy one to do. But you have to bite the bullet and do it. The alternative is to just bypass the core altogether, but then you'll have no heat and defrosters that won't be as effective.

MDchanic

Removing a heat-only heater core is a whole lot easier than removing an A/C heater core - less ducting, and the boxes are smaller and easier to get around.
I've done both on 69-72 A-bodies, and, basically, you just get up under the dash, wish your hands were the size of a 6-year-old's, and take the darn thing out.

The factory manual is quite clear.

- Eric

jaunty75

I'll bet, though, that 1973olds98's car has A/C. I doubt many 98s, even back in 1973, were made without A/C. It was a luxury car, after all, and what better defined luxury than having air-conditioning?

I actually wondered about the A/C vs non-A/C issue in this situation, but the manual makes no distinction in the procedure between removing the heater core from an A/C-equipped car and from one without it.

MDchanic

Duh.

Repeat to self:
Must actually read.
Must actually read.
Must actually read...

1973olds98

Mine does have A/C,, I have the glove box and rh trim section off,,,,And i do have the same book u speak off...I also have the front seat out of my car so i can easily move around while trying to get the bolts off...By looking at the manual i just go around the perimeter of the box and take out the screws correct...

jaunty75

That's exactly the way I read it.

With all of the pieces you have already removed, I'm guessing it should be fairly easy to get at. I'm also guessing that, once you start into it, it will be fairly obvious as you go what you need to do to remove it. If you pull on it and it still won't come out, something somewhere is still attached, and you find it and disconnect it. Etc., until it's all the way out.

MDchanic

Yes, BUT, it is probably sealed to the firewall with dumdum or some similar non-hardening putty-like goo, so you may have a bit of a pull to start it coming off.

Save the dumdum and reuse it.

(If you ever wanted to change your firewall insulation, this would be the time.)

- Eric

jaunty75

Yes, good point, there will likely be some sealant there.

1973olds98

lookin on top of the heater box there looks like all kinds of levers or something,,I just hope when i get it back together everything works..

MDchanic

I don't have my '73 manual in front of me, but I believe that ONE of those levers is connected to the temperature control lever (and removable by unscrewing a 1/4" hex head screw that holds a clip), and the others are connected to the vacuum diaphragms.

This would also be a good time to test all of those vacuum diaphragms to make sure they don't leak, and that they move the doors properly, and to test the selector switch to be sure the vacuum is being directed to the right places and that the hoses aren't leaking.

The details are all very well spelled out in the book.

It's easiest if you've got a hand vacuum pump with a gauge, but you can do it just by sucking on the hoses if need be.

- Eric

1973olds98

Job completed

It was alot easier then i was thinkin..There is a total of four bolts that hold the heater box to the firewall,,,The bolts on the bottom right corner and the top right side are visable from inside the car..Th other 2 use a stud that goes through the firewall and is held in by a nut and is reachable on the engine compartment side of the firewall,,,After removing the rh trim panel with glove box,,and removing the support bar,,,,The heater box drop right out....thanks,,

jaunty75

Glad to hear it went so well. It doesn't sound like you had to remove any control cables. Is that true?

1973olds98

When the box drop out i held it and was looking at the cables and vacuum lines being careful dont to damage it...I rested the heaterbox on the floor of the car,,,Reached around and seen how the heater core was mounted to the box,,,It is held in by a clip and uses 1 srew to hold it in...After i loosen it the core popped right out....I popped the new back in....And attached it back to the firewall....The cables and vaccum lines were untouched.....I started the car and checked to see if there were any leaks...Everything seemed to work fine......

1973olds98

If anyone needs my help tackling the same problem let me know,,I will help

NorTown Olds

COOL! GOOD job! Learned lots here; glad it went so smoothly. My only question is; where did you get the "new Heater core"?? Did the quality look the same and fit well etc??

1973olds98

Got it from autozone for 30.00,,,It looks just like the one I took out,,,Same size and everything