# heater core



## Topkat (Sep 9, 2010)

I wheeled my 67 Goat into the drive way and stuck a hose to the large tube on the heater core. The connection was miserable and water squirted all over me and the engine compartment.(stop laughing lol)
At 1st nothing happened.Then I got a small trickle. Then a good amount of water came out all orange colored. I stopped a bit then more orange water. All the while my wife watching the interior for leaks.
After a bit water started dripping slowely from this weird little ........whosmadinky. (looks like that's what it's for?)
Then a bit started comming out of the heater outlet on the hump.
But, the "potting" around the tubes in the engine compartment is pretty loose so maybe thats where the water's comming from. around the sides of the tubes?
I had a lot of pressure going on.
Thanks


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## geeteeohguy (Feb 2, 2008)

Okay---we've got potting and hump issues here. Here's what's going on, if I got it right: the potting must be putty, or dum dum, around the heater tubes. it is not meant to hold coolant inside the heater core. It is there to stop underhood air from entering the heater box. The rusty water dripping out of the whosmadinky onto the hump has nothing to do with the potting. It is water leaking from your blown heater core down the pivot shaft of the heater plenum door. You need to remove the heater housing and replace the heater core. While you're at it, you can clean and lube all the heater plenum doors and levers, get all the rust out of there, and have a nice, clean, warm heater for the next 20+ years. After you get all this done, you can have a Christmas toddy....just don't get potted!!!


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## 05GTO (Oct 6, 2004)

geeteeohguy said:


> Okay---we've got potting and hump issues here. Here's what's going on, if I got it right: the potting must be putty, or dum dum, around the heater tubes. it is not meant to hold coolant inside the heater core. It is there to stop underhood air from entering the heater box. The rusty water dripping out of the whosmadinky onto the hump has nothing to do with the potting. It is water leaking from your blown heater core down the pivot shaft of the heater plenum door. You need to remove the heater housing and replace the heater core. While you're at it, you can clean and lube all the heater plenum doors and levers, get all the rust out of there, and have a nice, clean, warm heater for the next 20+ years. After you get all this done, you can have a Christmas toddy....just don't get potted!!!


:agree

In order to save $100 I had a radiator shop pressure test my original heater core when they serviced the radiator on the 66, long story short, I put the car back together, cranked it up and guess what? The core was leaking into the passenger floor board. I spent the better part of 2 days removing and replacing the hood, inner and outer passenger's fenders to install a new heater core. 

Consider the $100 a cheap insurance policy,


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## Eric Animal (Oct 28, 2007)

:agree change it now....not after the car is finished and your new carpet is saturated with coolant!


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## Topkat (Sep 9, 2010)

Let me get this straight............ water dripping from that hole FOR SURE means the heater core is smoked and that water did not get in there by another route?


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## jetstang (Nov 5, 2008)

If the cars apart, replace the core, especially if its clogged and no water is coming out the return when you shoot water in, it should flow 100% without a great connection.
My 66, I took the hose off and the fitting moves when I wiggled the hose. I dont' have to pressure test it to know that its junk..


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## 05GTO (Oct 6, 2004)

Topkat said:


> Let me get this straight............ water dripping from that hole FOR SURE means the heater core is smoked and that water did not get in there by another route?


It's possible for water to have leaked into the heater box if your gaskets and seals are worn out. If you change the core most of the aftermarket suppliers also sell heater box gasket kits,


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## jetstang (Nov 5, 2008)

Pressure check the core and see if it leaks. Block up one hose, fill the core, then apply pressure and look for leaks. 120 PSI is too much, try 15, so regulate the pressure.


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## geeteeohguy (Feb 2, 2008)

Look---the car has sat for years. It's partially disassembled right now. While it is possible that water got into the heater box past the firewall seals "potting", it just makes good sense to put a new heater core in it and clean up and lube the heater box doors and hardware. Why do this job after the new carpet is trashed and the car is all together? This is one place on a GTO (like a cheap throw-out bearing) that you can't afford to cut corners. The labor to re-do the job is many times the cost of the part. Plus, after it's all done, you can get POTTED!!!


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## Topkat (Sep 9, 2010)

Ok, sounds like a plan. I really had to force the hose on there and got no flow at all at 1st.
As for potted.......(MWAAAAAAAAAAAAAA)
That begins in 8 more days when I go to CA for Xmas and to pay a last visit to the GTO's grave site to hunt missing parts.
Rock on my Mentors !
:cheersarty::cheersarty::cheersarty::cheersarty::

:cool
:seeya


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## Topkat (Sep 9, 2010)

er................what is it I need to lubricate?
I got both covers loose, dam ! that bolt behind the fender is a pain!!!!!!
I am sure glad the blower motor dosn't need to come out,


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## Chris Holabaugh (Jan 18, 2009)

When my 65 GTO was apart I replaced the heater core so I would not have the hassle later on. I was able to get one through the local GM dealer. You can replace it without removing the inner fender. You just have to have a mirror and allot of patience. The reason I know this is that did it that way on my wife's 64 Tempest back in the early 70's.


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