Coolant Leak
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,142
Likes: 0
From: Spring Grove Illinois
Coolant Leak
After a drive to the gas station,I park the car and notice a stream of antifreeze comming from under the vette...I can see nothing from the top side...It appears to be coming from the a/c box on the firewall...Is this possiable??? I'm going to get under there to pinpoint it but that is where it appears to be coming from..The floor of the car is not wet so I ruled out the heater core..What else is in there? I looked in the FSM not a real big help there...Any Ideas
Safety Car
Joined: Jan 2008
Posts: 3,939
Likes: 1
From: Vero Beach Florida
If it's coming from inside the box seems like it would be heater core related maybe just not bad enough yet to leak inside. Remove the hoses and by pass the heater see if that stops the leak.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
There are 2 pipes comming out of the heater core as you know, just at a guess from your avitar it looks as though youve got a 1990, so if this is the case, one will connect to the surge tank ubove the HVAC system where its mounted on the firewall, and the other will go to the water pump if i remember right (i really cant remember exactly where the heater core is fed from, but im pretty bloody sure the heater core returns into the surge tank)
Take a look at this pic of a surge tank where ive labled the connections:
That is for a later model than an L98 system, but the relevent parts should still be easily related. Check all around this area, especially the 2 big connections on the bottom side of the surge tank, and also the delivery line to the heater core, cause i reckon around this area is where you may find your leak.
I find it hard to believe it could leak ouside the car if it was the heater core and not either
A: smell of hot coolant inside the car, and B: leak from the HVAC system onto the carpet.
That is not to say it wont, but i find it hard to believe it could.
Take a look at this pic of a surge tank where ive labled the connections:
That is for a later model than an L98 system, but the relevent parts should still be easily related. Check all around this area, especially the 2 big connections on the bottom side of the surge tank, and also the delivery line to the heater core, cause i reckon around this area is where you may find your leak.
I find it hard to believe it could leak ouside the car if it was the heater core and not either
A: smell of hot coolant inside the car, and B: leak from the HVAC system onto the carpet.
That is not to say it wont, but i find it hard to believe it could.
Last edited by Casethecorvetteman; Jun 17, 2009 at 08:01 AM.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
If that is the case, the leak is quite likely to be in that area, especially if the hoses are old or the surge tank its self is the factory original unit.
Team Owner
Joined: Jan 2003
Posts: 20,301
Likes: 240
From: Summerland B.C. Canada
Don't rule out the core, just yet. GM was kind enough to place a piece of foam on the foot-well panel, just below heater box. Probably holds a gallon, before it's starts dripping from the panel. 
The "stream" does however, make it sound like something else.
Time to explore
It's an 86.
The "stream" does however, make it sound like something else.
Time to explore
It's an 86.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,142
Likes: 0
From: Spring Grove Illinois
Thanks Guys ..Yes like Dan said it's an 86....Case Good to hear from ya again Mate...I'll get it up in the air tonite...Only leaks when system has pressure..so I'll have to idle her abit...Will post results
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
No worries mate, you should be able to see abit of a trace of where it may be coming from though, just have a look before you fire it up and get it all warmed up, you dont want to be under there if it lets go!!
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Drifting
Joined: Apr 2007
Posts: 1,810
Likes: 0
From: NJ
I've got the same issue with my 94 
i had some antifreeze trickle down onto the passenger carpet and have read that a quick fix would be to bypass the heater core but my question is....does this fix also need to have the dash poulled out as if you were replacing the heater core and if so? why not just replace it if youve already gone through all that trobule of removing the dash? unless the hoses to do the quick fix are located under the hood without the dash having to be removed?
i had some antifreeze trickle down onto the passenger carpet and have read that a quick fix would be to bypass the heater core but my question is....does this fix also need to have the dash poulled out as if you were replacing the heater core and if so? why not just replace it if youve already gone through all that trobule of removing the dash? unless the hoses to do the quick fix are located under the hood without the dash having to be removed?
Safety Car
Joined: Jan 2004
Posts: 3,759
Likes: 8
Was it leaking to the ground, or just crud behind the engine? I've noticed black crud below the distributor of my 89. The crud looks like wet black gunk.
