draft

[dab67]

Not sure if this is the correct forum to post this query. I completed changing the heater core and put in new carpet in my 67. On the passenger side there is a draft coming from under the dash that drives my wife nuts!!!!!!!!!!!! I checked to see if the kick panel vent was closing and  sealing properly and it is. I checked to the best of my ability to see if the doors on the heater were working properly regarding the defroster and heat vents and they appear to be. I have no clue where this draft is coming from. Could the plastic "Y" tube used for the flow of air for the heat and defroster be damaged causing this problem? Or is it something that I am missing completly. 

Thanks CRG!

dab67

[Sauron327]

 Although obvious, the firewall pad( excellent condition I assume) needs to be kept in position to maintain a proper seal when re-installing heater box. The kick panel also has a seal behind it which may be deteriorated or not put back in when the car was restored.

[dab67]

Sauron:

Yes to both questions. The seal on the kick panel was repllaced as well the the firewall pad.If feels like it is coming from between the back of the dash and the firewall. There is about a 4 or 5" gap between them. That is why I wonder if it is the "Y" tube.

dab67

[Sauron327]

  My writing tends to be pragmatic.  First you have to stop the source of the" draft". Which would be the flappers in the box. If their throw is incomplete the gap will allow infiltration. Any binding or pivot points not operating smoothly due to corrosion will hinder operation. Throw can be adjusted on the top of box. Cables should be disconnected at these points and heater control levers operated independently of the box to verify free movement of cable within sleeve. Have mice resided in box causing obstruction? They will leave material deep within box at flapper location. These factors combined with the possibility of misalgned y- pipe should be investigated. With fan on high there should be little or no leakage around y-pipe when felt at junction to box.         Sauron

[JohnZ]

There is ALWAYS outside airflow into the heater from the plenum; if the foam seals on the air doors in the inside heater case have deteriorated/disappeared, it won't seal, and you'll get a continuous flow of outside air from the heat outlet.

[Sauron327]

 I agree with John Z. Apparently I was not technical enough and chose inappropriate adjectives.  By stopping the "source" I meant just that. The "source" which is from the plenum (hence plenum induction system)  must be stopped. Components in the heater box achieve this objective. Best to inspect prior to installation.

[dab67]

John and Sauron:

I'll check the plenum for the seals. Other than that everything else appears to be working and sealed correctly. I will also pull the "y" pipe. But all this will now to wait until the fall! It is time to cruise!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Dave