2 mystery air/vacuum/something else? lines. help!

[1990LTD]

this one came from the smog pump. you can leave it open since it's one way.

[gadget73]

I wouldn't trust it. Those valves leak. There should be a tee in the cruise control plumbing. One side goes to the cruise servo. One side goes to the vacuum tree, and the last one goes down toward the smog pump. Its not quite a tee, its a check-tee. There should also be a one-way valve in the line between the tee and the smog pump. Move that regular one-way valve to replace the tee. You should then have a hose from the vac tree on the firewall to one side of the check valve, and the line to the cruise servo goes to the other side. You'll have to orient the valve correctly or the cruise won't work. Arrow should point towards the vacuum tree.

If you don't have the second check valve, just get a connector and throw out all that tee and check valve crap in the smog pump/cruise plumbing.

[BerniniCaCO3]

Hey gadget,
I admit I'm a bit more confused than ever. Mind giving me a call at 410-802-9014? If you could walk me through what you're talking about while I'm looking at it?

[BerniniCaCO3]

Alright, just to make sure I'm on the same page.
First pic is the fender-mounted vacuum canister you're referring to?
Out the top of the photo --pointed to the right towards the engine in the car-- is the cable that goes to the throttle body, must be the cruise control line from a solenoid built inside the canister?
Out the right of the photo is one line that terminates in the side of the yellow check valve in question.
To the bottom of the photo is a line that seems to come from the fuse box, and also terminates in the side of the yellow check valve.
Out of the vacuum canister are two more lines. One just loops from one part of the canister to another, the other makes a beeline for the firewall.


Second photo just shows the check valve itself. A cluster of vacuum lines seem to come off from the right: two of those come from the side of the check valve itself, one of course going to the vacuum cruise control canister, the other going under the fuse box.
The other lines come off the tree that's behind the check valve. I never touched them, so where the come from/go to won't be misplaced.

Third photo is as good a photo of the vacuum tree as I could get....
Lots of lines there. They should all be correct though.

Back to the second photo. I just have a vacuum cap now on the front of that check valve.
I must just be getting confused...
One reply said that the air pump had a line that went there.
Another reply seemed to suggest that one of the lines from the cruise control vacuum canister went there, but I honestly don't see any available lines left!

If the front of the check valve was fed from the air pump, then cool, just leaving it capped off is what I should do?
If it needed vacuum from somewhere off the intake, though, then I've got a line misplaced elsewhere.

thanks for the clarification!

[BerniniCaCO3]

mind you, this is all nicely blockaded by the intake and the hood which are both back in place, now.

If I can just leave the check valve capped off, and everything will work, and there will be no vacuum leaks, that'll definitely be the easiest thing; rather than tracing tees and other check valves and rerouting lines that I can barely make out behind the intake, let alone move and mess with.

[1990LTD]

first pic is the cruise servo. the vac reservoir on a 90 (89 and under they were actually canister shaped...aka the soup can) is directly to the left in that picture, on 90-91 they are combined with the relay box.

[BerniniCaCO3]

ah, so that's why it seems to disappear under the relay box.
I should look for a disconnected line coming from under the relay box then?

[86VickyLX]

ah, so that's why it seems to disappear under the relay box.
I should look for a disconnected line coming from under the relay box then?

Not under under it, but around it.

[BerniniCaCO3]

yeah, there's just one line coming out of the vac reservoir.
It connects to the side of that check valve. I'm sure I've never moved it; never had to, to remove the engine.

Back to the first question: is there anything important that should go to the front of the check valve, or, did that get fed by the air pump and just capping it off solves everything.