Richard Cooper

I have a water/antifreeze drip on my passengers side floor. I know its the heater core leaking, my question is can I just didconnect both heater hoses fron the block and plug the holes until winter time when I can replace the core. Also, does anyone know what size threads are needed to plug the holes where I will be removing the hoses? I will also remove the fuse from the fuse box so the heater/cooling fan does not run for nothing right now.
I have had the 81 for 15 years and have NEVER used the heater and the AC has been removed a LONG time ago. TIA

69 Chevy

I believe 1/2NPT threads on 3/4" heater hose fittings and 3/8NPT on the 5/8" hose. But best to remove the existing fittings and take them to the parts store for comparison to new plugs.

I also believe your model has a steel floor. It would be wise to remove carpet/insulation so you don't promote floor corrosion all these many months until you dig into the heater core replacement.

Easy Mike

Yes.

You can buy two rubber plugs for this. They slip over the engine fittings and close off with clamps.

BKbroiler

Since the plugs are pipe plugs, you can buy them at Home Depot type stores. You know you're never going to change the heater core.

Richard Cooper

BKbroiler,
i think you are correct, like I said I have NEVER used the heater/AC so I think I will just leave them blocked off. I have changed a heater core in a friends 81 and had to remove the dash, not fun.
Thanks to all for the replys, enjoy the rest of your weekend.

Scottd

Most parts stores sell a plastic bypass hose connector...Just plug the input hose into the output hose and forget about the heater core.

boeing46

I've mostly owned older GM cars and the heater cores almost always end up leaking. They are a part that will eventually leak. Why in the heck couldn't they make them easier to change? I have seen so many that people have just bypassed the core because not only is it difficult to change but expensive to have it done. This problem is not an if it will eventually leak but a when will it leak. Do other makes of cars have the same problem or come up with an easier placement for repair? I would think an electric type of heater could have been invented that's easy to get to. Hmm?

tonystar1

I had this issue come up today, did an emergency loop with the heater hose. I'd like to replace the darn thing. Any suggestions? Thanks in advance. (1971 Convertible is the car, and her name is Jezebel).

boeing46

I would suggest people replace the core as soon as possible. Many just procrastinate and most don't think about it till it's cold as hell. If you don't know how have it done at a good radiator-a/c shop. It ain't cheap but should be done. It really looks Bubba to see a bypassed core IMPO.

tonystar1

I sure wouldn't want to be a bubba, especially since I live in Reno and think of most of these folks as hillbillies. I did look up a video on YouTube today, and found a good one. Heater core replacement on a '74 Vette, no a/c. Six nuts from the Engine Side of the firewall. I'll have to remove my washer fluid top half, and maybe the wiper door vacuum actuator, but a hell of a lot better than doing the dash route.

JWR11

I am completing a body off resto on my 1969 350/350hp non air vette.
I replaced the heater core with information obtained from various threads on the internet and found that many owners suggested that it was easier and faster to replace it from the engine bay. I followed in kind and the job was quick and easy. Of course with no air and the body
off the frame, it made for good access. Remove the blower housing and you will see a retaining clip on the left side of the heater core. Be sure to pry it slightly to the left to release the two small teeth that hold it into the heater core frame. Remove the clip and you can remove the heater core starting by gently pulling the left side first then slide it to
remove it from the clip on the outlet side of the heater core.
Hope this helps fellow C3 owners with the same task!

great68

Look up, heater core by pass AGAIN, in the Search this thread in General and you can see a way to by pass your heater problem until you can fix it. I did it to mine cuts down on the heat too! Hope I explained it right.

tonystar1

At JWR11: Thanks for that, it helps as the YouTube video was on a 74 and he didn't have the wiper door vacuum to deal with. It took me a while to get that right, and I don't want to mess with the actuator. Can I ask if you had to deal with that? Thanks from Tony.