TO replace or not replace (heater core)
Thread Starter
Heel & Toe
Joined: Sep 2009
Posts: 18
Likes: 0
From: Mountain View CA
TO replace or not replace (heater core)
Hello All,
Thanks again for your continued help; I'm thinking about replacing my heater core.
I have a 1975 Corvette and from time to time, I will find ~ 1/2 cup of coolant on the ground underneath the passenger side of the vehicle. I showed a mechanic my heater hoses (that's where it's dripping from) and he was sure my heater core is leaking.
Is this a difficult project?
Expensive etc? I may not know what I'm doing, but I'm more than willing to put in the time to learn how to do it.
Is it a relatively simple process, just very time consuming?
I was told to just link the two hoses together and zip tie them to the car; is this acceptable? From what I've read, the heater core is pressurized; will this prevent coolant leaking into my passenger compartment?
I don't use the heater to begin with, so I can live without it... how can I be sure it's the core?
Thanks again for your help...
Semper Fi!
Felix
Thanks again for your continued help; I'm thinking about replacing my heater core.
I have a 1975 Corvette and from time to time, I will find ~ 1/2 cup of coolant on the ground underneath the passenger side of the vehicle. I showed a mechanic my heater hoses (that's where it's dripping from) and he was sure my heater core is leaking.
Is this a difficult project?
Expensive etc? I may not know what I'm doing, but I'm more than willing to put in the time to learn how to do it.
Is it a relatively simple process, just very time consuming?
I was told to just link the two hoses together and zip tie them to the car; is this acceptable? From what I've read, the heater core is pressurized; will this prevent coolant leaking into my passenger compartment?
I don't use the heater to begin with, so I can live without it... how can I be sure it's the core?
Thanks again for your help...
Semper Fi!
Felix
Melting Slicks
Joined: Dec 2000
Posts: 3,363
Likes: 303
From: Lansdale 19446 PA
2024 C3 of the Year Finalist- Unmodified
St. Jude Donor '10-'11, '15, '19
I will tell you a little "Bubba" I did when I discovered my heater core was leaking (the day before my clubs big show).
I put an adjustable wood clamp on each hose to cut off the water circulation. Removed each hose from the heater core. I forced a piece of capped 1/2" copper tubing in each line a couple inches from the core lines. Put a clamp on each hose where the copper tubes were & reconnected to the heater core. This lasted me the whole summer - I replaced the heater core over the winter.
One suggestion IF you ever replace the heater core - take the new core to a radiator shop and have them pressure tested AND reinforce the solder joints where the tubes attach to the core. I learned this the hard way on both my 69 & 78! Installed straight out of the box - both leaked at that poorly soldered joint!
And no, I didn't find the replacement to be too difficult.
John
I put an adjustable wood clamp on each hose to cut off the water circulation. Removed each hose from the heater core. I forced a piece of capped 1/2" copper tubing in each line a couple inches from the core lines. Put a clamp on each hose where the copper tubes were & reconnected to the heater core. This lasted me the whole summer - I replaced the heater core over the winter.
One suggestion IF you ever replace the heater core - take the new core to a radiator shop and have them pressure tested AND reinforce the solder joints where the tubes attach to the core. I learned this the hard way on both my 69 & 78! Installed straight out of the box - both leaked at that poorly soldered joint!
And no, I didn't find the replacement to be too difficult.
John
Thread Starter
Heel & Toe
Joined: Sep 2009
Posts: 18
Likes: 0
From: Mountain View CA
I will tell you a little "Bubba" I did when I discovered my heater core was leaking (the day before my clubs big show).
I put an adjustable wood clamp on each hose to cut off the water circulation. Removed each hose from the heater core. I forced a piece of capped 1/2" copper tubing in each line a couple inches from the core lines. Put a clamp on each hose where the copper tubes were & reconnected to the heater core. This lasted me the whole summer - I replaced the heater core over the winter.
One suggestion IF you ever replace the heater core - take the new core to a radiator shop and have them pressure tested AND reinforce the solder joints where the tubes attach to the core. I learned this the hard way on both my 69 & 78! Installed straight out of the box - both leaked at that poorly soldered joint!
And no, I didn't find the replacement to be too difficult.
John
I put an adjustable wood clamp on each hose to cut off the water circulation. Removed each hose from the heater core. I forced a piece of capped 1/2" copper tubing in each line a couple inches from the core lines. Put a clamp on each hose where the copper tubes were & reconnected to the heater core. This lasted me the whole summer - I replaced the heater core over the winter.
One suggestion IF you ever replace the heater core - take the new core to a radiator shop and have them pressure tested AND reinforce the solder joints where the tubes attach to the core. I learned this the hard way on both my 69 & 78! Installed straight out of the box - both leaked at that poorly soldered joint!
And no, I didn't find the replacement to be too difficult.
John
Hi John,
Thanks for the reply, why the wood clamp? I know I'm asking the same question twice, but can't I just disconnect the two heater hoses and put a U joint between them to close the circulation? I don't understand how / where I should do this bypass? I just thought I would disconnect the two hoses and link them together?
F
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
Most people would consider changing the heater core a challenging project. Since you don't use the heater, you can simply remove the heater hoses entirely and install pipe plugs at the intake manifold and water pump. No bypass is required. My car has this setup with no problems.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Hi John,
Thanks for the reply, why the wood clamp? I know I'm asking the same question twice, but can't I just disconnect the two heater hoses and put a U joint between them to close the circulation? I don't understand how / where I should do this bypass? I just thought I would disconnect the two hoses and link them together?
F
Thanks for the reply, why the wood clamp? I know I'm asking the same question twice, but can't I just disconnect the two heater hoses and put a U joint between them to close the circulation? I don't understand how / where I should do this bypass? I just thought I would disconnect the two hoses and link them together?
F
Thread Starter
Heel & Toe
Joined: Sep 2009
Posts: 18
Likes: 0
From: Mountain View CA
Most people would consider changing the heater core a challenging project. Since you don't use the heater, you can simply remove the heater hoses entirely and install pipe plugs at the intake manifold and water pump. No bypass is required. My car has this setup with no problems.
F
Thread Starter
Heel & Toe
Joined: Sep 2009
Posts: 18
Likes: 0
From: Mountain View CA
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Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
This pic is from before I removed the AC evaporator & housing. You can see the two plugs. They are just pipe plugs from Home Depot, 1/2 inch and 5/8 inch I think. It reduces clutter but doesn't add horsepower.
Thread Starter
Heel & Toe
Joined: Sep 2009
Posts: 18
Likes: 0
From: Mountain View CA
F
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
One plug is on the intake manifold just below the rad hose connection in the picture. The other is down on the passenger side of the water pump. They are the same locations where your heater hoses connect to the engine.
Le Mans Master
Joined: Jan 2003
Posts: 6,575
Likes: 1
From: Tuttle OK
Cruise-In VIII Veteran
http://www.corvettefaq.com/c3/heatercoreremoval.pdf
Advanced
Joined: Jul 2007
Posts: 72
Likes: 2
When my heater core failed ( I wanted to postpone the core replacement work until later) I went to an auto supply store and asked the clerk if he had a heater hose that was 5/8 on one end and 1/2 on the other. He found one and when I got home I cut the hose to make short loop of hose right at the engine end. I attached the hose to the fittings on the engine with the original hose clamps. I removed/discarded the old hoses from the end of the heater core. I ran the car this way for about 11/2 years. As for the heater core replacement it is not a difficult task but is long and tedious. There are several good references on the internet about the steps to do this job, many with pictures taken during the process.
Thread Starter
Heel & Toe
Joined: Sep 2009
Posts: 18
Likes: 0
From: Mountain View CA
Here's a post I made sometime back. It's on an '80. Yours has a split dash, so it will be a bit different. Once you get to the heater box, I believe they're the same though.
http://www.corvettefaq.com/c3/heatercoreremoval.pdf
http://www.corvettefaq.com/c3/heatercoreremoval.pdf
Best,
Felix
Racer
Joined: Jul 2008
Posts: 305
Likes: 0
From: Riverside CA
I just finished mine yesterday, and here's the thread
http://forums.corvetteforum.com/c3-t...ater-core.html
http://forums.corvetteforum.com/c3-t...ater-core.html
