1) "I had replaced the vacuum line from the manifold to the vacuum
canister, I =
even replaced the fitting on the manifold."
Been there, done that, lots of new vacuum hoses.
2) "The distribution door (parts book page 26-12 item 4) in my opinion is=
a
lousy =
design. Also the box plenums are snapped together but lots of holes for a=
ir
to escape.
What I have done is make a new aluminum door and mounted to the upper
plenum. =
After snapping the plenums together, I sealed the openings with silicone.=
On my testing, I had good flow from both sides of the plenum."
As I suspected it looks like I could find lots of work in the air
distribution system.
3) "On the A/C box, I was going to use a Clasco kit that I bought at the
GMCMI =
rally at Laughlin but decided to go another way. I added a stainless door=
=
behind the heater core. I thought I needed to have the door operated by t=
he
temp door but the air flow will swing the door from cold to heat
positions."
When I had my heater box out I built my own "max air door" (controlled by=
the recirc pot) and aux duct below the dash. It does an exellent job of
bypassing all the dash distribution system. It provides the kind of air
flow I
expected from the system. On max air I can feel air flow as far back as t=
he
dinnette. I'm real happy with that one.
Thanks Manny. Looks like I need to spend some time with the dash
distribution system.
Regards
Gary Zingle
1973 GMC 26 foot
canister, I =
even replaced the fitting on the manifold."
Been there, done that, lots of new vacuum hoses.
2) "The distribution door (parts book page 26-12 item 4) in my opinion is=
a
lousy =
design. Also the box plenums are snapped together but lots of holes for a=
ir
to escape.
What I have done is make a new aluminum door and mounted to the upper
plenum. =
After snapping the plenums together, I sealed the openings with silicone.=
On my testing, I had good flow from both sides of the plenum."
As I suspected it looks like I could find lots of work in the air
distribution system.
3) "On the A/C box, I was going to use a Clasco kit that I bought at the
GMCMI =
rally at Laughlin but decided to go another way. I added a stainless door=
=
behind the heater core. I thought I needed to have the door operated by t=
he
temp door but the air flow will swing the door from cold to heat
positions."
When I had my heater box out I built my own "max air door" (controlled by=
the recirc pot) and aux duct below the dash. It does an exellent job of
bypassing all the dash distribution system. It provides the kind of air
flow I
expected from the system. On max air I can feel air flow as far back as t=
he
dinnette. I'm real happy with that one.
Thanks Manny. Looks like I need to spend some time with the dash
distribution system.
Regards
Gary Zingle
1973 GMC 26 foot
