1959 non-ac heater core removal

[390 man]

After installing seat belts last week, I am now on to my next project. Last fall I noticed a coolant leak inside the car. As a temporary fix, I used a bypass hose at the water pump. As a Michigan resident I now feel the need to address the leaking heater or control valve. So far I have removed the heater inlet. From in the engine bay. Moving to the inside of the car. My Cadillac shop manual, first item remove glove box. No problem. Second item. Remove upper instrument panel cover and cluster as described in Section 12, note 51, 1 through 9. My manual does not show this. Does anyone have the information that I need to complete this task? Thank you much, Dave.

[76eldo]

You should not have to remove the cluster and the dash.

If you remove the cables from the links on the heater valve inside of the heater core enclosure inside of the car you do not need to remove them at the controls.

It's a difficult job and the heater control valve is a part of this puzzle too.  It's actually one of the heater hose connectors that pokes through the firewall.  It bolts to the heater core and has an O ring type seal.

Plan on sending yours out or at least have it leak tested on the new core.  You could have a good core and only need the valve.

There is an access plate you can remove to try to look inside.

We just did a 1960 with AC and that's more complicated by far.

The hardest part is getting the heater core inside box up off of the floor vent.  You will need to peel up the carpet to see what I mean at the top of the hump.

In this case, the shop manual is a very poor reference for doing this job.

Brian

[59-in-pieces]

Dave,
Have you ever heard of or read "easier said than done".
Well you have now - just slash your wrists, and put a pan under the coolant leak - empty when needed, and be glad you don't have an AC car.
Note 51 with its 9 steps will give you access to the inside of the fire wall behind the dash, and make the repair easier, with allot of work and it's a pain in the butt, because the heavy instrument cluster is tied to the dash pad by 4 bolts, along with its 2 cables - speedo & tripometer, and the pad is tied to the chrome dash board by 6 or so screws - one side to the other.

OK, back to being serious and business.
Can you actually tell where the leak is.
Does the heater core leak or the heater control valve.
Does it leak when the engine is hot or any time or when the heater valve is turned on or off with the cable from the Heater control assembly, bottom lever - moves R&L from off to warmer - next to the steering wheel on its right side.
Have you pulled off the cover with the fan motor attached to it in the engine compartment.

When I get the answers to these questions, I may be able to offer up more advice and some pics.
Good luck, and have fun,
Steve B.

ps
Brian is on the right track too.

[Scot Minesinger]

A tip I use every time a remove from inside dash heater core (as opposed to from under hood removal like in the 65-70 Cadillacs) has to be replaced is blow out the coolant with compressed air before disconnecting the hoses.  This way it is much lass likely to get coolant drips and such inside the car.  Did this on a 72 Eldorado.

[390 man]

Yes I have another 59 and a 60, both with AC. I use the heater control gingerly, hoping for no leaks from the control valve. I cannot tell where the leak is coming from, but looking at the heater core from underneath the hood, it looks decent from that side. I just purchased this car in the fall so I don't have a lot of history as to when it leaks. I peeked inside the access door, when the heater core was still hooked up. It was not leaking an excessive amount. My main issue at that time was I was getting no flow through the heater core. The hoses were not even getting warm. Can I remove the heater core without removing the dash? Thanks again Dave.

[MY 59]

Hey 390 man,
I had to change both the core and tap on my AC 59, as well as all the vacuum pots etc. It was a pain, but I just took my time and paid attention to what I was doing
the rubber grommets where the Bowden cables went in, as well as the vacuum lines themselves, the foam padding and gaskets were all disintegrated so I replaced them (made my own gaskets)

I am sure yours will be different as it is non AC, but whenever I do something new like this, I just pay attention (photos if necessary) and take my time

there is oodles of help here if you get stuck

[76eldo]

Dave,

Yes.  You do not need to remove the dash.

A non AC car is much easier.

You don't even have to remove the box under the hood, just several of the fasteners.

The cables are tricky so be sure to take photos and mark the cables because you won't remember what a photo will show you.

Brian

[n2caddies]

Brian is correct. You do not have to remove the dash pad to get the box out. In this case the manual makes it way more difficult than it really is. Did my non AC  59 last year and it was not bad. Took out the glove box and the glove box door to give me more room. It was pretty straight forward. Took off the outside cover on the firewall where the fan and the vacuum pod is. Disconnected the Bowden cables and air ducts on the inside and a few screws  and the heater box with the core inside came out. Had the valve rebuilt by Jim Tucker in Hemmings  Magazine and put in a new core. Made new gaskets from foam I got at the hardware store.  Pictures are a must. Just take your time and make some notes to help put it all back.
Randy

[390 man]

Thank you for the replies. It's good to know that I won't have to remove the right side dash panel. Thanks Dave.

[59-in-pieces]

Dave,
I am a belt and suspenders kinda guy, and don't like to do things twice.
So here are a few suggestions.
Replace the vacuum actuator(s) - making sure the new cable(s) attaches as the old - often the actuation wire is broken and could be the reason for poor or no air flow, at least for one function heat/defrost.
Replace all of the vacuum lines - one end at a time to not confuse which start end goes to which destination end.
Lubricate the cables within the sheaths, and all the pivot points from levers to actuator to heater valve, and inside/outside the plenums - some use WD40 (which initially works, but over time it breaks down the rust and may clump later, and drag), others use spray silicone.
Replace the felt around the directional defrost-heater door - to create a good seal and avoid air leaking between functions.
I can't recall, but there is likely at least one plastic vacuum switch (gray) with tubes in the heater defrost assembly, where the control levers actuate it/them - a drop or 2 of clock oil inside the tubes of the switch will help keep the vacuum switch working efficiently.
Had the no flow of air issue sited above, and once again - found by pulling off fan side firewall plate, heater core jammed with leaves and debris - removed them, blew out core, and it flowed like a champ (assuming you already know the fan is working).
Have fun,
Steve B.

[390 man]

It's out. I got the name of Joe Hudacek from Hemmings. I talked to him this evening. I will ship him the whole assembly, heater core and control valve. He said he will rebuild the control valve and recore the heater. Steve, I should have been more clear in my description. My problem was with coolant flow through the heater core. Not air flow. Thanks Dave.

[390 man]

Thanks to all who responded to my post. You can't tell by looking at it but there's hot air blowing in that Cadillac. Next item on my list, rear axle bearings. Thanks again Dave.

[76eldo]

Nice going!  Nothing like taking on a tough job and getting it done successfully.

Great looking flattop!

Brian