Coolant Leak - Heater Core?
Thread Starter
8th Gear
Joined: Mar 2005
Posts: 8
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Coolant Leak - Heater Core?
I will have to admit that I am a novice, but I have a large coolant leak in my '68 non A/C around the passenger side wire wall that is puzzling me. I don't see any signs of a coolant leak in the cabin under the dash where the heater core is and the hoses to the heater core appear to be good.
I am thinking about bypassing the heater core for now if it is the problem so I can drive till a replacement comes, but the amount of coolant on the garage floor (estimate at least a gallon) makes me a bit nervous. I would appreciate thoughts from folks with more experience than I. Thanks.
I am thinking about bypassing the heater core for now if it is the problem so I can drive till a replacement comes, but the amount of coolant on the garage floor (estimate at least a gallon) makes me a bit nervous. I would appreciate thoughts from folks with more experience than I. Thanks.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
I will have to admit that I am a novice, but I have a large coolant leak in my '68 non A/C around the passenger side wire wall that is puzzling me. I don't see any signs of a coolant leak in the cabin under the dash where the heater core is and the hoses to the heater core appear to be good.
I am thinking about bypassing the heater core for now if it is the problem so I can drive till a replacement comes, but the amount of coolant on the garage floor (estimate at least a gallon) makes me a bit nervous. I would appreciate thoughts from folks with more experience than I. Thanks.
I am thinking about bypassing the heater core for now if it is the problem so I can drive till a replacement comes, but the amount of coolant on the garage floor (estimate at least a gallon) makes me a bit nervous. I would appreciate thoughts from folks with more experience than I. Thanks.
Its very possible one of the brass tubes going into your heater core has a cracked solder joint and that's why its only leaking on the engine side of your fire wall.
Thread Starter
8th Gear
Joined: Mar 2005
Posts: 8
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Drifting
Joined: May 2012
Posts: 1,353
Likes: 44
From: Calgary Alberta
I'd have a second look at the hoses, turning them over to look for very small imperfections - it doesn't take much of one for a hose to leak under pressure. Also look closely at the heater valve. The valve can leak at its joints. When that happens on a non-A/C car, the coolant can travel down the frame rail a bit and then exit the car underneath the firewall. That can happen even with the the car parked and the system depressurized. Start small and work your way up. If it ends up being the core, the swap doesn't look to be too bad a job on a non-A/C car (there's a good thread here somewhere, maybe posted by Paul74, can't recall).
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
I'd have a second look at the hoses, turning them over to look for very small imperfections - it doesn't take much of one for a hose to leak under pressure. Also look closely at the heater valve. The valve can leak at its joints. When that happens on a non-A/C car, the coolant can travel down the frame rail a bit and then exit the car underneath the firewall. That can happen even with the the car parked and the system depressurized. Start small and work your way up. If it ends up being the core, the swap doesn't look to be too bad a job on a non-A/C car (there's a good thread here somewhere, maybe posted by Paul74, can't recall).
http://www.corvettefaq.com/c3/heatercore.html
Thread Starter
8th Gear
Joined: Mar 2005
Posts: 8
Likes: 0
Thanks for the link and efforts documenting the work. I was looking to access the core from dash so these pictures cleared it up. More of the core is in the engine compartment then I realized so that maps out to dripping off the frame.
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Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
I drove the 1979 for 17 years and did that job twice. It is not terribly difficult. Good luck!