69 Kick Panel Vents Full Of HOT Air...

[Jamie F.]

Is there supposed to be some type of seal that goes between the firewall cowl and the front fenders on both sides in front of the kick panel vent openings?
Hot engine air is passing around the cowl and going into the kick panel vents when they are open and pouring hot air into the passenger foot area.
It's cooler in the car on a hot day when I close these vents than leave them open.
This doesn't seem right. It seems like there should be a seal or wall there.
I know the fender side louvers on a 69 were supposed to vent hot underhood air out the sides, but it seems like the flow is also around the cowl and out the kick panel vents.
Is anyone familiar with this area of the car?

[Jack H.]

Re: 69 Kick Panel Vents Full Of HOT Air...

The vent valves have rubber 'sandwiched' between the two valve case half stampings. The rubber is what's supposed to seal off air flow, but it can/does deteriorate over time like that shown in the picture...

Dr. Rebuild sells an overhaul kit (fresh die cut rubber, you drill out the valve rivets, remove the old rubber, install fresh, and re-rivet the valve panels back together.

Also, you might have 'invasion' pathways into the heater plenum from the engine compartment. One that's 'famous' is the die cut foam seal surrounding the refigeration lines serving the evaporator on A/C equipped cars...

[Jamie F.]

Re: 69 Kick Panel Vents Full Of HOT Air...

Jack, thanks for the reply. Those doors seal fine and the seals are fine. It's what's on the outside of them that isn't, hot underhood air comes around the cowl and into those vents.
I can contort my arm and reach down around the firewall cowl between the fender by the body mount and put my finger into those vents, so the hot air can get there too. Doesn't seem right like a seal or panel is missing?

[Jamie F.]

Re: 69 Kick Panel Vents Full Of HOT Air...

Further Jack, when moving I can put my hand down in front of the kick panel vent and feel the hot engine air pouring in. When I close the vent doors it stops and is much cooler down there.
I've looked at pictures of the cowl area with the fenders removed and at that area in the AIM, and everything seems copasetic, but something is amiss!

[Jack H.]

Re: 69 Kick Panel Vents Full Of HOT Air...

Well, absent pouring over your car, I gave you my best shot off the top of my head...

But, if you expect the heater plenum to be stone cold (ambient temp) while you're driving, I think that's a bad expectation. With the car in motion, there will be 'some' ram effect from outside air being driven into/through the cowl.

Couple that with the heater core being driven with engine coolant 'just in case' you decide to call for heat and ANY leaks between the heater plenum and the cockpit will allow outside ambient air to flow picking up stray heat from the heater core.

What I'm saying is just because the temperature of air inside the heater plenum is above ambient doesn't prove there's one or more leaks between the engine compartment and the heater plenum. But, there sure could be leaks in addition to decayed seal integrity...

[Michael W.]

Re: 69 Kick Panel Vents Full Of HOT Air...

I believe that there should be a seal near the rear lip of the hood that would stop engine compartment air from entering the plenum at the base of the windshield.