Water leaking onto passenger side floorboard.

[Rageman]

Hello there. I'm new here, and I have a problem with my truck that has me stumped.

For reference, my truck is a 1988 Chevrolet Cheyenne, Single Cab. I recently pulled my carpet, and found and excessive amount of water has been leaking into the cab on the passenger side. It appears the water (and it is water) is coming from the gasket that seperates the heater core box to the firewall. It's been raining everyday since I've had the carpet out, so I have not been able to verify if this is rain water or something else. I've attached a picture that shows the location of what I'm talking about. I can see where this protrudes into the engine bay, can I seal it off with some silicon, or is this a bigger issue? Help is needed, feedback is appreciated.

EDIT: This picture is looking underneath the passenger side dash, just below the heater core box.

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[bluex]

http://www.gmt400.com/forum/showthread.php?t=15928

Check this thread, should help you out.

 

[98_k1500]

^ yup. Thats your culprit if its not coolant.

 

[Rageman]

http://www.gmt400.com/forum/showthread.php?t=15928

Check this thread, should help you out.

Was your issue fixed by repairing the HVAC vent under the cowl? Silicone around the box, and silicon the cap?

 

[bluex]

Was your issue fixed by repairing the HVAC vent under the cowl? Silicone around the box, and silicon the cap?

Yes it was. It was a pain to do but that's what it took to finally stop the leak.

 

[Rageman]

Issue fixed. It was the HVAC intake. While i was in there, I noticed that the RTV up against the firewall (on the inside cowl area) was also deteriorated, so I re-did that as well. Whichever it was, it's now fixed. Thanks for the helps. Reps.

It seems I'm unable to rep you for whatever reason. Virtual hi-five.

 

[bluex]

No problem man, glad you got it fixed up.

 

[Rageman]

OK. Bit of an update here. As it turns out, that didn't fix the problem. To be honest, I think it was leaking, and it fixed one leak, but another leak continued.

The heater core gasket has gone bad-ish..and water was coming out the tip of the A/C drain, rolling back towards the firewall, and seeping in through the gasket. I couldn't find a rubber hose with a thin enough wall to fit (the heater core return hose is too close the HVAC drain), so I bored a piece of 1/2" copper pipe until it fit snuggly over the drain line. Worked like a champ. This keeps the water from rolling back to the firewall. Leak fixed for now, I'll replace the gasket if/when the heater core goes.

Reps anyways. Thanks!