body and interior Heater Box and Hot Air

[2002#3]

1974 tii...

 

I did a total rebuild of the heater box and installed a new heater control valve (HCV).  The dash levers work well and, believe me, the box can produce copious amounts of hot air.  However, only hot air comes from the box, even when the HCV is closed (lever at COLD).  I checked the HCV:  by visual examination through the HCV openings the HCV seems to open completely at HEAT and close completely on COLD.  Still only hot air is produced out.  Of course, I can stop the hot air by closing the flat.  Could the hot air be coming from the engine bay around the cowl and into the fan?  I assumed my replacing the cowl-to-hood weather strip would prevent that; no change.

 

I will appreciate your sage advice and wise counsel.

 

Larry 

 

[stone02]

this may sound silly but which way is the

big arrow on the heater valve pointing. also

with you move the heat lever is the cold air

flap also opening to allow direct air in without

it being forced thru the heater core.

let us know.

stone

[2002#3]

The HCV arrow is pointing inward, toward the heater box.

 

Moving the HEAT/OFF lever opens and closes, respectively, the footwell flaps in the box and controls air directly out of the box and into the footwell (the source of the hot air to which I referred).  Am I missing a "cold air flap" that you mentioned?  I cannot seem to find a cold air flap or visualize where cold air should be entering, other than directly thru the fan.

 

Thanks for your advice and patience...

 

Larry

[JerryC]

The cold air flap Stone is referring to is inside the heater box. It allows straight outside air in, bypassing the heater core, when the temperature lever is set to cold.

There is a heater box refurb article on this website, but the photos seem to have been misplaced.

 

[2002#3]

Hmmm...  I understand.  Your comment sounds logical and probably is just the ticket.  I might have screwed the pooch when I rebuilt the box, i.e., incapacitated this cold air flap thingy.  Sounds like the HEAT/OFF lever moves an inner flap(s) to mix/direct outside cold air and inside hot air proportionally.  I cannot wait to perform yet another ever-so-much-fun-and-easy heater box removal and installation.  

 

Thank you so very much.

 

Larry