[Dick Boneske]

Does a '63 Bonneville convertible use manifold vacuum for anything besides power brakes, PCV, & distributor vacuum advance? I know the A/C-equipped cars use vacuum for the controls. How about the regular heater without A/C?

I'm building a Tripower for a '63 in California and need to know whether it needs the small vacuum line off the center carb tee. You can see the small vacuum line in the middle picture on this '62 setup I restored recently.

Thank you.

[Pontiac62]

My 62 is an A/C car, but my previous 62 had vacuum for the defroster flapper door only. I don't know about the 63.
Les

[Dick Boneske]

Probably the same for '63 as '62.

[Stuart]

Did 1963 have two different styles of regular heaters? In 1961 there were Direct-Aire and Circ-L-Aire heaters; one was purely mechanical controls and the other had vacuum control for the flapper. I don't know how many years they continued those two options.

[Dick Boneske]

I asked the owner of the Bonneville to check if there is a vacuum line from the carb to the firewall.

[Engine-Ear]

Dick (and Stuart), Circ-L-Aire heater requires a manifold vacuum signal. There should be one vacuum line heading into the rubber vacuum bulkhead and I think there is another vacuum line coming from the heater control that runs along the engine side of the firewall going to the round vacuum diaphragm on the heater box.

...do you have a '63 HVAC manual?

Not that I am the last word on any of this, but I have never seen Direct-Aire system on a US-built '62 or later DarkSider.

I HAVE seen this system on CANADIAN-built PRE-'63 Pontiacs, but again, never on '63+ examples.

(Dick, I had a chuckle when you clarified that this is a convertible!)

[Dick Boneske]

Thanks for the replies everyone.

Matt, I'm glad the convertible comment amused you! I don't know why I stated it was a ragtop, but that's just the way my fingers guided me!!

Dick