Mystery Canister On Wheel Tub?

[Jerry Shuck]

On the wheel tub of my '64 Riviera are some unused mounting holes and a plinth.  I have seen some sort of monstrous canister in this are in photos of '63 Rivieras.  Could someone tell me what it is and should it be in the '64 engine compartment? Option of some sort?

[TexRiv_63]

Vacuum storage tank, think it was just used on A/C cars.

[Jerry Shuck]

Looks like that.  I have an AC 1964 Riv but it did not come with it.  My circulation doors are all mechanical.  Do you think this was strictly a '63 feature?

 

[RivNut]

As said above. Vacuum canister. 1963 Only.

[arnulfo de l.a.]

I have a vacuum canister in my ac 65 but its smaller and made of plastic. 

[RivNut]

 64 and 65 have the small plastic canister on the right inner fender.

[telriv]

That was a vacuum storage canister for the power brakes on a '63 Riv. ONLY.

NO '64's or 65's had one.

 

Tom T.

[Jerry Shuck]

Very interesting. Quite a difference in sizing of the different vintage canisters.  My '64 is about a quarter of the size of a '63.  Thanks Gents.

[Craig Balzer]

22 hours ago, TexRiv_63 said:

Vacuum storage tank

Well -- -- that is peculiar.

I don't have a great photo of it, but you can see the top of the vacuum reservoir is this photo.  It even has the dimple on the one end - in my case on the top.

Thus is in my 1972 Jaguar XKE V12, but a very similar appearing tank was on the first XKE's in 1961 (mine has nipples for three lines; the early ones had two).

 

 

Edited September 4, 2022 by Craig Balzer (see edit history)

[Jim Cannon]

On 9/4/2022 at 1:09 PM, Gerald Shuck said:

Very interesting. Quite a difference in sizing of the different vintage canisters.  My '64 is about a quarter of the size of a '63.  Thanks Gents.

The '63 vacuum storage can is there to store vacuum just for the power brake booster, so that you will have a couple of brake applications with boost after the engine stalls.  Later boosters have this storage volume built into the booster can itself, so no external storage bottle is needed.

 

The 1964 and later vacuum storage canisters are just for the flapper actuators on the Heating & A/C system.  There is no backup vacuum for brakes there.

 

This small reservoir was added so that when you accelerate hard (to get on a highway, up a hill) and your engine vacuum drops, all of the A/C flappers do not return to their starting position (mainly it was dash vent air suddenly going down to the floor vents, and then when you let off of the gas, they all flip back to air coming out the dash vents again).  It gives the A/C system a small vacuum reserve to hold everything where it is supposed to be.  That's why it's so small.

 

1963 owners noticed that their air dropped down to the floor when they stepped on the gas hard for a long-ish time, then came right back when they let up on the gas.  Buick installed the vacuum reservoir in 1964 and beyond to fix that. I have added one to my '63 so that the dash air comes out correctly when I "step on it".

Edited September 6, 2022 by Jim Cannon (see edit history)

[Jerry Shuck]

Damn Jim,  you know your stuff.  Thank you for the education.  

[1965rivgs]

  The reservoir is present to charge the diagrams when called for by the operator.   The check valve, which is independent of the reservoir on a '63 and integral with the reservoir in '64 - '65, is what prevents the vacuum in the system from depleting when intake manifold vacuum falls due to throttle opening. Without the check valve the vacuum level in the smallish vacuum reservoir on the '64-'65 would disappear almost immediately upon heavy acceleration....just a reservoir will not prevent that.

Tom Mooney

Edited September 5, 2022 by 1965rivgs (see edit history)