The vacuum line is not connected to anything

[wpatters1229]

2003 with 5.4 engine. There is a small vacuum line that is in the rear of the left side of the engine bay. It comes off a connector with two other larger vacuum lines. It is a hard plastic line and the end is cut at a diagonal. Can't find what this is all about. It has a vacuum on it at idle but when plugged does not make a difference in how the engine runs. Is this a vent or what? It is about 6" long. Here is a picture I found on the internet

 

[whtbronco]

I suggest it's one of the vacuum lines for the front 4wd vacuum hubs. If I'm correct the solenoid for the vacuum lines is on the left side of the picture you attached mounted on the firewall. Mine broke years ago as well and I just re-connected it with a 2" piece of vacuum hose.

 

[BlackCoffee]

I don't think this is the vent for the 4x4 hubs. That is usually down by the shock column, hard to see, and is turned down to prevent water from entering (like on a ship). The line you are looking at should have a T on top. On one side is goes behind the battery to the air box. The other side snakes across to the valve on the right side of the throttle body.

 

[wpatters1229]

I suggest it's one of the vacuum lines for the front 4wd vacuum hubs. If I'm correct the solenoid for the vacuum lines is on the left side of the picture you attached mounted on the firewall. Mine broke years ago as well and I just re-connected it with a 2" piece of vacuum hose.

No the line I am looking for to find out where it goes is the one that has a diagonal cut on the end and the end is sitting on top of the battery post. It is a thin plastic line but does have some vacuum. So far I have plugged it up but it must either connect to something or is some kind of vent but then why would it have a vacuum? It is connected to a fitting that has two other large rubber lines connecting to a check valve. plugging it or not does not seem to make the engine miss.

 

[Hamfisted]

I'm gonna go with dash vent solenoid supply line for a hundred Alex . If it has a vacuum on it with the engine running it's a supply line to something. The only hard plastic line in that area is the dash vent control supply line. Hopefully you find the other end of it poking out of the pass-thru grommet there just below it on the firewall. You can splice them back together with a short piece of rubber vacuum tubing. Can you post a picture of your actual broken line ? In the internet pic you posted you can see the broken supply line sticking out of the pass-thru grommet in the background.










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[whtbronco]

I'm gonna go with dash vent solenoid supply line for a hundred Alex . If it has a vacuum on it with the engine running it's a supply line to something. The only hard plastic line in that area is the dash vent control supply line. Hopefully you find the other end of it poking out of the pass-thru grommet there just below it on the firewall. You can splice them back together with a short piece of rubber vacuum tubing.

Oh my goodness that was hilarious. Thanks for laugh.

That HVAC related line seems to break fairly commonly.

 

[wpatters1229]

I know what you are talking about. I bought my 2000 expedition from my neighbor who said the vents in the dash only blow out the defroster vents. I fixed the broken hose you speak of with a hose connecting the two pieces and everything now works fine on the dash. He was told by the Ford dealership they would have to pull the dash apart to find what was wrong. This hose I am looking at is on a 2003 and it looks different than my engine bay. But I will look more carefully since I may have missed it since the hose is not cracked like mine was and has a distinct diagonal cut on the end. I also do not believe my brother-in-law said anything about the dash vents not working right.