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Discussion Starter · #1 ·
Greetings, This spring I stripped the interior out of my 81 TA to sound deaden it only to find the passenger side floor pan rusted out,UGH...... Well got a new pan and had the whole passenger side replaced.

I assumed the rust out was due to leaking T-top seals as its common. We had a pretty good rain today and I put plastic under the t-top and over the glass taping the perimeter to the glass and body. Went out and water in the floor. Started looking around under dash and the insulation behind the heater enclosure is wet and I saw a drop of water drop down.

I had a guy replace the heater core some time back and I'm wondering is there some type of sealer that should be between the box and firewall or is there is something above that in cowl that I'm missing? I checked the exit where heater core goes into engine compartment and the material around the hoses is broken so I plan to seal those. any other ideas?

I did pull the kick panel with vacuum chamber for ac when I pulled interior. Is it possible that somehow it has left the cowl flap open or would this make a difference. Would seem that you would use vent when it rains on occasion. Any help would be appreciated.
 

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The kick panels needs to be sealed to the hull, the cowl flap doesn't matter, water runs down the cowl sides (and into the unsealed kick panels) but also could be a rust pin hole inside cowl plenum chamber. Some more investigating to see where it my come from or end up.
 

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Probably not what you want to here, but.... I went thru 3 heater cores before we got 1 that didn't leak.
 

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Hello, thanks for the replies. The heater core was replaced sometime back , ( years ago). I was thinking of heater core except the leak happened with the engine off and no pressure in system. The interior is still out so no water coming through the kick panel vent hole. The windshield was replaced years back so that's a possibility I hadn't thought about.

I don't have a garage so the car is in the weather It's possible its been slowly leaking for years. We had a real hard rain and that's when I noticed the leak. I saw a drop come off the top of what I assume is the air box where the heater core sits. The insulation was saturated that's between the box and firewall. I noticed some water coming down the firewall about 2 inches from the passenger kick panel.

I parked the car in my sons garage for now and will begin the painstaking job of tracking the leak. Figure I'll pour some water here and there off cowl and also the windshield and see if I can pinpoint it that way. Sucks because I was ready to start sound deadening the interior and installing the sound system. Now I cant but better to find it now than get the carpet in and have to start all over.

Thanks again and if anyone has any other ideas let me know
 

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You don't need pressure to get a leak. Things cool, shrink, and sit for long periods. But also, a heavy downpour will find water coming through places it wouldn't often be seen, it would find pinholes in the cowl plenum floor, and also been able to sit under the windscreen and find and pinholes under there too. Even if the windscreen seal is bad, water would only sit under it on dash top, unless it finds a hole. Corners are worse as can often be damp on both sides, and no drips.

Is the dash out also? Even if it was, can be hard to see anything going on. You may need to have the windscreen resealed, and an excuse to have them clean up and look under it. Also, take the plastic mesh grille off the cowl area, shine a torch around, or take photos with phone and flash and look for issues. Wipe it all all with a clean rag, it should be nice red primer, or satin black on an 81.
 

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Discussion Starter · #7 ·
You don't need pressure to get a leak. Things cool, shrink, and sit for long periods. But also, a heavy downpour will find water coming through places it wouldn't often be seen, it would find pinholes in the cowl plenum floor, and also been able to sit under the windscreen and find and pinholes under there too. Even if the windscreen seal is bad, water would only sit under it on dash top, unless it finds a hole. Corners are worse as can often be damp on both sides, and no drips.

Is the dash out also? Even if it was, can be hard to see anything going on. You may need to have the windscreen resealed, and an excuse to have them clean up and look under it. Also, take the plastic mesh grille off the cowl area, shine a torch around, or take photos with phone and flash and look for issues. Wipe it all all with a clean rag, it should be nice red primer, or satin black on an 81.
Dash not out, didn't know about no pressure leak in heater core. Only thing that makes me think it may be elsewhere is only noticed when it started raining. Its been in the garage for about a week. I'll go check it tomorrow it see if water has leaked into floorboard.
Thanks
 

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For sure, if it had seen rain, it was then seen dripping from above, and was water, not coolant, I'd be be looking there at this point.

Yep, depends on the type of leak if under pressure or not. Sometimes the expanding parts can find a leak, they can also start to seal them. A bit like head gasket leaks and similar, often weep out when cold and sitting, will seal when engine up to temp. Not always. Just enough to be annoying to chase faults at times.
 
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