80 450sl - What is this (broken) vacuum line to? Help ID part (Pic) - PeachParts Mercedes-Benz Forum

supercanuck · #1 05-29-2008, 12:03 AM

I have a 1980 450sl, and lately I've had some issues with a rough idle and a major lag when I give it gas. As I was checking all of my vacuum connections under the hood, I ran across some remnants of a blue/gold vacuum line and then I found the other end where it broke off.

However, I don't know:
a) Where the other end of the vacuum line goes to
b) What the name of the part is that the line connects to on the hose to the air filter (the red piece in the picture).

Can someone please help me out in identifying these parts and where the vacuum should hook up to?

Thanks!
Zack

donbryce · #2 05-29-2008, 10:47 AM

supercanuck · #3 05-29-2008, 11:50 AM

I guess that helps

It was late

supercanuck · #4 05-29-2008, 04:24 PM

Can anyone at least tell me what the part circled in red is? It's on the hose from the top of the air filter housing.

Thanks!

supercanuck · #5 05-30-2008, 03:37 PM

Someone in another forum told me that this part is the Air Check Valve - can anyone confirm that?

If that is the case, where is the other end of the vacuum line supposed to connect to?

Philoprof · #6 05-31-2008, 09:54 AM

Quote:

Originally Posted by supercanuck

Someone in another forum told me that this part is the Air Check Valve - can anyone confirm that?

If that is the case, where is the other end of the vacuum line supposed to connect to?

I can't identify that vacuum line, but my 380sl has blue and red vacuum line with one end open that seems to go down to the air pump. My car never had a problem starting or running. So, if your car was running well until now, and you didn't do anything that could have broken the line -- I think you'd see the other part if you did -- it's very possible that the line is not broken and was never connected to anything.

450slcguy · #7 06-01-2008, 11:43 AM

Quote:

Originally Posted by supercanuck

Can anyone at least tell me what the part circled in red is? It's on the hose from the top of the air filter housing.

Thanks!

That is the air check valve. The vacuum line off that valve(circled item) goes to the throttle valve housing below the air sensor. The easiest way to find where that connects is to follow the vacuum hose that goes from the top of the distributer to where it ends. You'll see 2 vacuum connections there and 1 more to the left of there. Replace all the rubber vacuum hoses in that location, as they will all be shot. You'll need some 8" long nosed skinny pliers to dig into there to make the connections, as it's real tight.

Just buy some black rubber vacuum tubing at autozone or somewhere for $5 bucks and start splicing in new pieces. You'll probaly also need to replace some of the hard vacumm tubing as it gets britte and breaks. You can buy that locally although the colors will differ. Start splicing in the new rubber hose and tubing as needed. There will be several 3 way and 4 way rubber vacuum unions, those should all be replaced. You can buy all that here or elsewhere. Maybe $30 bucks total. A couples hours work and done. Easy