Alternative Vacuum Canister Options ?...and other ?'s

[Little Jon]

I've got a vacuum leak SOMEWHERE and am gonna have to track it down.

While I'm in the process, I thought I'd go ahead and replace some of the components to the system, just to be on the safe side regarding possible future leaks.

I have to admit I know NOTHING about vacuum systems except what I've read on this forum.

So here are my questions:

I've read that the vacuum can on my left inner fender-well can be replaced with a newer, plastic canister from a later car, but what to look for in a replacement?

Any particular size of canister or model of source car to look for? Mine has the one outlet nipple that the tubing runs off of, so I assume I want another with a single nipple, right? Does canister size matter?

Also, I've read several metions of a "Tree" in the system....I assume this is a coupling of some sort for several vacuum lines to meet at, but where is it located on my car and where do I go to get a quality, new replacement?

Finally, do you just go to your local auto parts store and ask for vacuum tubing? Is it pre-cut to match the car's existing routing to the various components or do you need to do this yourself?....If so, are there any tricks to doing it correctly?

It'd be a huge help if there was some sort of vacuum system diagram that I could reference...Any suggestions there?

I know, TONS of questions from the noob, but it's hotter than satan's play-pen up here and I'd really like to get my A/C up and going!

ANY help will be greatly appreciated!

-Jon

[1987cp]

Wow! I don't know that anyone's ever put that much thought into vacuum reserve canisters.

IIRC, the nice oblong plastic things are from late Boxes and possibly from Aeros and stuff. And several members own EVTMs from various years and some (Tiggie comes to mind) have even posted scans of a few pages.

Parts stores sell rubber vacuum tubing in rolls, or you can get fancy and get plastic tubing in rolls and separate rubber ends. I don't recommend the plastic route, though, since I had 100% of my rubber ends disintegrate on me. I'd be shocked if anyone supplied pre-made vacuum tubes, especially as only Saab owners have the patience for that sort of expense for super-basic vehicular needs.

You can often get bulk rubber hose suitable for vacuum signals from your favorite hardware store or home center. Cheaper that way.



BTW? If you suspect the vacuum reserve canister of leaking, trace its tube to the tree on the firewall, and remove it and cap off the now-vacant nipple. Repeat for any other components you suspect. Automatic parking brake releases are possibly a more common source of leaks, though in that case you would hear the leak from inside the cockpit.

[Little Jon]

Thanks, 1987cp!

What effect will capping off the line to the canister have though? Will any of the vacuum actuated systems still work?

-Jon

[1987cp]

All the canister actually does is provide a vacuum source when manifold vacuum is low, as during hard acceleration. I have it disconnected on my sedan right now, and the main effect I notice is that the A/C blows out the floor vents when I'm on the gas.

[Glen]

You can replace the "can" with a newer plastic box type. It is in the same place as yours, it will have 3 relays in a box on one the side of it. (Those will work for the headlight fix.) The "vac. tree" is on the fire wall behind the engine just a little to the left as you look from the front of the car. It should be white tube looking thing, about 3 inches long, with 5 or 6 tubes coming off both sides. There are 3 or 4 sizes of vac tubing. Ya just have to get the right size and start replace what is leaking.

[Little Jon]

Thanks, Grant!

Uhhh...."Headlight Fix"??

I see you are here in Kentucky. Where abouts is Grant's Lick?

-Jon

[87gtVIC]

All he means is that there is a nice place for adding some extra relays, specifically some relays to take the load off of the headlight switch.

[Little Jon]

Thanks, David!

I've found some more info on here about this and am taking notes....Funny that as many of these things as FOMOCO built, they didn't seem to make manyrunning changes to correct what ammounts to a handfull of niggling problems...*shrugs*

I gotta admit though....So far I love this big beast!

-Jon

[Glen]

About 20 miles south of Cincinnati.