Vacuum canister

[BBoswell]

I have a question which may have an obvious answer but for the life of me I can't figure it out. My '57 Custom 300 has a vacuum canister under the passenger side fender. The is nothing hooked up to it and I cannot find a reference to it in my shop manual. The odd thing it is that it only has one vacuum port. Can anyone tell me what this was for and how it was connected with only one port?

[SkylinerRon]

Sounds like someone added it to help with the vacuum wipers.
The only vacuum on a 57 are the power brakes and wipers and the brake can is on the drivers side
inner fender, with 2 ports.
Later models with vacuum heater doors used this type of cannister and an extra can be used to crutch a
leaky system in a pinch.

Ron.

[BBoswell]

Were '57 wipers vacuum? My wipers are electric. I'm old and not near as sharp at I once was but I still don't understand how the canister can it be of any help with only the one port?

[Ford Blue blood]

Look at it as a storage container.  Extra volume.  Run the vacuum line through a check valve to a "T".  One line from the T goes to the device the other goes to the tank.  When the gas pedal is depressed vacuum falls off, the check valve closes and you still have vacuum in the tank to run the wipers or brakes and as is the case with late model stuff the many accessories that require vacuum.

[BBoswell]

I learn something every day. I wasn't aware there was such a thing as a vacuum check valve. I will have to get one and give this a try.

My problem is dealing with a moderate size cam, new manifold and new Holley carb. Car runs great, but the minute you apply the power brakes to stop or put the car in gear the vacuum falls off and I loose all my advance in the distributor which makes the engine want to die. I can put a vacuum canister in for the power brakes like I did on my Ranchero . . . but this canister is already there and I thought if I could figure it out I'd give it a try.

Thanks for the info. Now all I have to do is find the check valve in this rather small town. Fingers crossed.