Mystery Orb

[CreativeNotice]

So mounted to the firewall, just behind the jack mount, in the far driver's side corner, is a small orb with one vacuum hose going to it and no outlet. Any idea what it is. My only guess is some kind of dissipation enclosure for the vac system.

C20 '85 350eng

[VileZambonie]

Vacuum reserve canister for vacuum operated accessories such as your heater controls.

[CreativeNotice]

So what's its exact function. Does it just stabilize pressure in the lines?

[eventhorizon66]

Its purpose is to generate alot of speculation and rumor from onlookers.  Actually, I believe "Mystery Orb" is its proper name.  So, lucky guess.


It stores a reserve vacuum to operate all the little HVAC vents, flappers, and doodads.

[ccz145a]

...so if your accelerating when you want to change from max to bi-level you won't have to wait until your foot is off the throttle.

[Lt.Del]

when i read the title of this thread "Mystery Orb", i expected to see a ghost in the truck 

[kenf729]

And just to be sure there is an outlet on the bottom going into the cab to the enviorment contorls...if not you have a vacuum leak...

[BigBadJohn]

I too was wondering this. I saw it in a camaro I just picked up and figured it was an emissions thing like the charcoal canister

[CreativeNotice]

ah, very helpful thank you.