2000 Chevy Blazer. I was doing some stuff under the hood today and I noticed this little hose was not connected to anything. I wasn’t sure if I hit or bumped it and knocked it loose but when my blazer is running I can hear it sucking air and I’ve never noticed it before so I feel like I did knock it loose by mistake. Just need to know if it’s supposed to be connected to something.

 

Do you have a round plastic ball mounted to the underside of the hood right there by it? I think that's where the hose goes. Some kind of vacuum reservoir

 

I will have to check in the morning, I don’t remember seeing any ball there but I could be wrong.

 

My 95 had one, and that's where that same hose went. Might have changed it up by 2000

 

There's a box it goes to in the drivers fender. Mine got disconnected. I put a plug in it, not affecting anything...

 

The vacuum reservoir is there so steady vacuum is applied too various controls and such during acceleration when vacuum drops

 

The vacuum reserve tank that hose goes to is mounted inside of the top rear of the driver's side fender. Difficult to see.

 

Check the link in my signature below for diagrams for the vacuum system on the 2nd gens. I've tried to maintain the first post in the thread so that others can benefit from what I learned about the system. I replaced all of my hoses in my 99 and it fixed an annoying issue with my HVAC system that I then learned was probably, unbeknownst* to me, making it so that my front axle was not engaging.

It is an easy fix to replace all of the under-hood vacuum hoses and well worth your time because they will eventually rot and start leaking.

To get that particular hose back on can take the use of an inspection mirror and a flashlight to make sure it is back in place.

* Isn't that just a great word; "unbeknownst"!

 

Huh. TIL later second gens had a different vacuum reservoir than early second gens