73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: CreativeNotice on June 04, 2009, 08:30:25 am

Title: Mystery Orb
Post by: CreativeNotice on June 04, 2009, 08:30:25 am
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

(http://farm4.static.flickr.com/3310/3595360630_5240283556_o.jpg)
Title: Re: Mystery Orb
Post by: VileZambonie on June 04, 2009, 11:55:00 am
Vacuum reserve canister for vacuum operated accessories such as your heater controls.
Title: Re: Mystery Orb
Post by: CreativeNotice on June 04, 2009, 11:57:50 am
So what's its exact function. Does it just stabilize pressure in the lines?
Title: Re: Mystery Orb
Post by: eventhorizon66 on June 04, 2009, 12:20:49 pm
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.
Title: Re: Mystery Orb
Post by: ccz145a on June 04, 2009, 01:13:40 pm
...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.
Title: Re: Mystery Orb
Post by: Lt.Del on June 04, 2009, 02:02:46 pm
when i read the title of this thread "Mystery Orb", i expected to see a ghost in the truck  ;D
Title: Re: Mystery Orb
Post by: kenf729 on June 04, 2009, 04:15:35 pm
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...
Title: Re: Mystery Orb
Post by: BigBadJohn on June 06, 2009, 01:15:58 am
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
Title: Re: Mystery Orb
Post by: CreativeNotice on June 08, 2009, 08:43:38 pm
ah, very helpful thank you.