69 Fog in the cabin

[Don W.]

I have a 69 427 coupe. I took it out for a run and had the haeter on. After I did some fast runs; the window fogged up and steam came out of the floor vent. I also had coolant dripping when I stopped. Is this the heater core that is shot?

Thanks,

Don

[Edward J.]

Re: 69 Fog in the cabin

Don, sounds like you hit it on the button.

[Don W.]

Re: 69 Fog in the cabin

OK, so what are my options here. I understand the the heater core replacement is a major project. Since I am one of the 10 to 15 million unemployed since Sept '09 and will not be spending $ at this time; I think my options are:

A) Not use the heater and keep all the controls in the off position
B) Disconnect the two hoses from the fire wall and connent them to each other. Flush out the heater core hose connections and then cap them with something
C) some other recommendation that you have

Also, what does it take to replace the heater core. I think it involves extensive disassembley of the passenger side interior.

Thanks,

Don

[Edward J.]

Re: 69 Fog in the cabin

Don, the best thing you can do is get a union and join together, or take the 3/4 hose and make a loop from water pump to intake fitting.

[John D.]

Re: 69 Fog in the cabin

Don, You both posted and answered your own question. Unfortunately you are correct in the assumption that the pass. side of the interior needs to go.
Get a good buddy to help you and the job should be done in a day.
Or go with your plan B. Disconnect it as a Corvette doesn't need a heater anyhow.
The guys get tired hearing this but I drove a 63 Coupe to work almost every day. In the winter time the last thing you needed was a heater as those coupes have a built in oven. JD

[Norm B.]

Re: 69 Fog in the cabin

Don,

Back in the olden days I used "B" a few times as a quick fix to get me home. It will basically keep a car running indefinitely so long as you don't need or want heat. Not sure exactly how the 427 is configured but the easiest way is to first decide which hose on the engine/water pump is easiest to get to or deal with. Pull it off there. Pull the other hose off at the heater core and plug it into where you pulled the first hose off the engine/water pump. You have now created a loop bypassing the heater core without having to connect the two hoses together.

I wouldn't worry too much about capping the heater core as it sounds like you are in for a replacement anyway.

My 2 cents.

Norm

[Joe L.]

Re: 69 Fog in the cabin

Don, the best thing you can do is get a union and join together, or take the 3/4 hose and make a loop from water pump to intake fitting.

Edward------


It's not quite that easy on a 1969 (except small blocks with copper/brass radiator). On all small blocks with aluminum radiator and all big blocks, the radiator supply tank is part of the heater hose system. That cannot be "by-passed". However, what can be done is to remove the hoses at the heater core and install a loop or otherwise join them together.

[Joe L.]

Re: 69 Fog in the cabin

OK, so what are my options here. I understand the the heater core replacement is a major project. Since I am one of the 10 to 15 million unemployed since Sept '09 and will not be spending $ at this time; I think my options are:

A) Not use the heater and keep all the controls in the off position
B) Disconnect the two hoses from the fire wall and connent them to each other. Flush out the heater core hose connections and then cap them with something
C) some other recommendation that you have

Also, what does it take to replace the heater core. I think it involves extensive disassembley of the passenger side interior.

Thanks,

Don

Don------

Does the car have A/C, or not? If not, replacing the heater core is not that big of a problem, especially for you since you have time on your hands right now.

Remove the right side sill plate, kick panel, and lower dash pad (this is the easiest part of the whole job).

Remove the center gauge cluster and radio

Remove the nuts, from the engine side of the firewall, that retain the inner heater box. Remove the inner heater box from the car. Remove heater core from the box and replace with new.

Since you're new to this repair, the job might take you the whole day, but it's very do-able.

You can buy a heater core for about 35-40 bucks. It'll be an "off brand" but don't worry about that. All of these are now "off brands" even if they come in a Delco or GM box.

[Edward J.]

Re: 69 Fog in the cabin

I was thinking small block, forgot about the overflow tank. I did mention a union though.

[Don W.]

Re: 69 Fog in the cabin

My car is a non-AC vehicle. Are there any good web site showing how to do the heater core. Also clock and voltage gauge don't work and I need to install the correct radio, which I have, so I may try and hit everything at once...Don

[Terry M.]

Re: 69 Fog in the cabin

My car is a non-AC vehicle. Are there any good web site showing how to do the heater core. Also clock and voltage gauge don't work and I need to install the correct radio, which I have, so I may try and hit everything at once...Don

I am not aware of a web site with instructions, but your copy of the FSM (Factory Service Manual) will have instructions and your copy of he AIM (Assembly Instruction Manual) will have drawings of the parts involved and how they fit together.

One additional recommendation, which JD hinted at earlier: Get the passenger side carpeting out -- remove that sill plate and seat and remove the three rubber plugs (carefully) from the toe board area. Thoroughly rinse the carpet and underlayment once they are out of the car, and put them in a warm place to dry. Thoroughly rinse the fiberglass on the passenger floor and remove (wet vac) the water. Leaving the coolant soaked carpet in place will damage the fiberglass and the carpet.

[Arland D.]

Re: 69 Fog in the cabin

Don,

Just replaced the heater core in the '82 last week because of the fog on the windshield and the familiar odor of warm coolant. The heater core was weeping slightly so it wasn't as serious as yours. As Terry mentioned, the Factory Service Manual is extremely helpful for this and hundreds of other tasks. You may want to consider replacing the hoses and some of the gaskets related to the heater system once you have it removed - Doc Rebuild provided an excellent package that worked perfectly. Regards,

Arland

[Jack H.]

Re: 69 Fog in the cabin

Sometimes you can get 'lucky' using a good brand of radiator stop leak additive... If the source of the heater core rupture is small, the stop leak additive just might work to fill the leak (either temporarily or permanently). My experience is it's maybe a 60/40 proposition...

But, it's a cheap and quick alternative to try versus the conventional approach of fully replacing the heater core. Also, if you DO get lucky and manage to seal the leak, I'd suggest simply draining your system coolant and replacing it after you add the stop leak additive (WITHOUT using a conventional flush agent) to purge the system of the residual stop leak additive.

Why? I've seen stop leak additives 'attack' and fill the safety pin hole bypass used by some thermostats. Not good!

[Don W.]

Re: 69 Fog in the cabin

I have the AIM and the Chassis service manual. Are there any seals or other item that I need to be aware of for the replacement?

Thanks,

Don

[Joe L.]

Re: 69 Fog in the cabin

I have the AIM and the Chassis service manual. Are there any seals or other item that I need to be aware of for the replacement?

Thanks,

Don

Don-----


The Doctor Rebuild kit has everything you need.