Mystery vacuum line, help identifying.

While replacing the plugs and wires today, I noticed a vacuum line hanging free behind the engine. I couldn't find any fitting that it should be attached to, but it has come off of something!

Can you help identify where this line goes? It comes off the vacuum "tree" on top of the manifold. I've highlighted its parent line with a green arrow in one photo, and that line appears to be labelled on the fan shroud as "ACSRV".

I have attached photos.













Thanks,
Al

Al, If I'm right that line that is disconnected goes to your vacuum reservoir for your cruise control. If you werent sure, the reservoir is the black rectangular thing dead center at the top of the firewall. There should be a little nipple thing underneath the reservoir. Also, It looks like that line needs replacing! Looks a little crusty  .

The 'T' is a check valve and one line goes to the cruise actuator and the other to the reservoir. Hope that helps!

Thanks, that sounds like a likely location now that you mention it. I'll check it out!

...and yes, replacing ALL the vacuum lines is on my short list. They all are a bit crusty   

Old car syndrome! Haha.

Verified, that was it! 30 second fix... the best   

Amazing how well the cruise control works again when its vacuum system is fully connected   

Here's another question though, are the vacuum check valves maintenance items, especially when considering that they are 20 years old at this point?
 
I'll be replacing all the old cracked/brittle/cracked vacuum lines under the hood in the next week or two and there is one or more of these cheap plastic vacuum check valves in there too.
 
I am a fan of "if it ain't broke don't fix it" but these guys are super cheap and wonder if after 20 years they really should be replaced, or if the OEM valve basically lasts forever and is recommended to just reuse if not malfunctioning.
 
As aside question: How would one verify/test that the original valve is fully functional?  These ones have three nipples instead of two, so I wonder how they can be successfully checked. I have my own theory, but thought I'd see what was recommended.



...it if is just cheaper/easier to replace it along with the old lines, no worries.

I assume these three nipple check valves of a similar design are all the same, and I don't need some esoteric special model valve?
 
One like this:

http://www.autozone.com/autozone/accessories/Help-Two-way-vacuum-check-valve/_/N-25hz?itemIdentifier=230927_0_0_


Thanks again!
Al

Ive never had a check valve need replacing. Some of my 80's cars have their original check valves! How to check if it doesnt work? Take it off, cap one end, try blowing through the other and vice versa.

Im glad it was a simple fix!

I think that's just a tree, not a check valve.

The check valves basically just have a spring and a flap inside them. The most I've ever needed to do was blast a little carb cleaner through one.