Help identifying unknown hose to nowhere! - PeachParts Mercedes-Benz Forum

glenlloyd · #1 01-02-2010, 12:35 AM

Posted this up on benzworld but thought I would add it here as well.

I pulled the car in the shop to replace the air filter and I found this black pastic hose with a rubber U shaped fitting on the end going nowhere. It comes from the radiator support area behind the passenger headlight and there's what looks to be a small translucent inline filter in this line. It runs up along the outboard edge of the air cleaner over to what I assume is the HVAC blower box and vacuum manifold and there it sits.

In the photo you can see there's a small stud mounted inside the trough next to the air filter box and this plastic hose has a small rubber lined metal hold down clip that I'm almost sure should be bolted to that stud. If the hose should be on the other side of that trough I have no idea where it goes. I've looked around behind the back of the air cleaner assembly but I can't find anything that looks like a nipple that this should attach to.

Any help on this would be appreciated, 1992 W140 w 603 engine.

Steve A

okyoureabeast · #2 01-02-2010, 12:50 AM

That looks like a vacuum hose.

Do you have any vacuum accessory that isn't functioning?

What happens if you suck on the line

Also when your car is running try applying vacuum to it. See what happens!

glenlloyd · #3 01-02-2010, 02:15 AM

Quote:

Originally Posted by okyoureabeast

That looks like a vacuum hose.

Do you have any vacuum accessory that isn't functioning?

What happens if you suck on the line

Also when your car is running try applying vacuum to it. See what happens!

When the car is running it doesn't seem to pull any vacuum. I haven't tried sucking on it....but I will try applying vacuum to it.

The hose ends up behind the headlight attached to some sort of valve thing with a few other hoses hanging off of it. In fact this hose, after the small inline filter thing, splits off into a Y with one going to the pod and the other someplace else...hidden under there.

thx
steve a

okyoureabeast · #4 01-02-2010, 03:19 AM

I'm sadly not familiar with your chassis and model car. I'm hoping someone will chime in pretty soon. However I am 99.5% positive that is a disconnected vacuum hose.

Sucking or using a mity vac achieves the same end result

The mity vac does it much more accurately.

glenlloyd · #5 01-02-2010, 12:17 PM

Quote:

Originally Posted by okyoureabeast

I'm sadly not familiar with your chassis and model car. I'm hoping someone will chime in pretty soon. However I am 99.5% positive that is a disconnected vacuum hose.

Sucking or using a mity vac achieves the same end result

The mity vac does it much more accurately.

I agree, it has to be vacuum, it uses the rigid plastic pipe which is often for vacuum as it doesn't collapse like other types of tubing.

I'll try and post up a pic of where this goes up by the headlight but it's -10F outside here right now!

regards
steve a

compu_85 · #6 01-02-2010, 12:46 PM

On the W126 black lines are generally vent lines that go to nothing. Where does the other end of that line go?

-Jason

Billybob · #7 01-02-2010, 12:49 PM

Sorry I don't know where that line would attach on the end with the rubber U, but being that "It comes from the radiator support area behind the passenger headlight and there's what looks to be a small translucent inline filter in this line." it is very likely a line that once provided ambient pressure filtered air to some device that on some occasions of its operation sort of "bleeds off vacuum". There will likely be some electriclly operated solenoid valve in the vacinity of the U hose end where it should be attached. When said valve operates in the static mode normally it probably supplies constant vacuum to something, when some control wants to remove vacuum the valve operates dymanically and functions to open an orifice to ambient air pressure thereby negating the normally applied vacuum force, the filter on the end of the hose fuctions to only allow clean filtered air to bleed into the vacuum source. This would prevent dirt and debris from clogging the tube end or making it down the tube and possibly clogging the operating mechanism of some valve.

Crazy_Nate · #8 01-02-2010, 12:57 PM

From looking at the EPC, it's definitely not related to the central locking system or power closing system - those are cabin / trunk. I'm not seeing that style connector in any of the EPC for a 140.134

The best help I can offer is this diagram from the EPC. There are several ones, and they contain a bit of parts "this item number is not valid for this model des.". So, it might not be exactly like the diagram. Hope it helps... I'm sure the chassis FSM (engine / vacuum diagrams) would be more helpful.

JimmyL · #9 01-02-2010, 01:08 PM

Let's count the replies on this thread where somebody posted with no familiarity at all with the car in question nor the issue at hand. You think somebody owns a Mercedes and didn't have an idea that the line in question might be a vac line?
This is the kind of spam choking this forum for awhile now!

and yes, I'M JUST SAYIN'.....
Somebody with a rod bender or W140 answer the poor guys question. You might also need to ask this in Tech Help section as there will be FAR more non-diesel W140's operable than rod benders, and this line might be familiar to them also....
Mini uncalled for rant over.....

*edit*
see, while I was typing Nate was giving good useful educated info!
Nice...

glenlloyd · #10 01-02-2010, 01:21 PM

Thanks Nate for providing the image, I believe it is shown in there although the curved U shaped fitting is not shown.

#668 is the small inline filter, #557 is the plastic tube and #534 is the small clip shown at the very bottom in my photo. #609 is not what's at the end of my tube. Perhaps someone has been in there and changed things...incorrectly...don't know.

The big question now is where is the correct #609 fitting and what does #609 go to and what is the function of this vac line?

As a side note the schematic doesn't exactly match up with what's going on near the right headlight. That doesn't mean that my setup isn't correct, just that there is a difference. I don't know whether this is due to someone having taken things apart and then not knowing exactly how it goes back together.

Thanks
Steve A

Crazy_Nate · #11 01-02-2010, 01:58 PM

Hey Steve,

The image is taken from the "EPC" - a very useful tool: http://epc.startekinfo.com/epc/

I signed up for 1 year, free. You just supply some info and a credit card (I'm not exactly sure why, they don't charge it). You might be able to find slightly more specific diagrams if you provide the VIN into the program. I provided a more generic W140 (140.134) with an OM603.971, however, there seem to possibly be differences in the years for this model which I can't discern at this moment.

The exploded diagrams seem to be pretty decent, however, they mainly just show which parts are what, not really where everything goes. The FSM diagrams from my W124 manual seems to be better, but, again they're different. I'm not sure about the W140 FSM.

Using the EPC is pretty helpful for talking directly to the parts guys at the dealership, should you choose to purchase parts there (or inquire about prices). Give it a try!

Cheers,

Yak · #12 01-02-2010, 02:36 PM

So JimmyL is also rogue post intolerant? Excellent...

x2 on the recommendation for the EPC site. Going off Nate's recommendation, but on page 6 instead of 8, is a small U-shaped hose that connects up to the EGR system. The hose is p/n 602 078 11 81 and says "from EGR valve to change-over valve." It otherwise matches the picture in hose shape and general location.

Look for an empty barb/fitting on the top of circular device on the front end of your intake manifold.

glenlloyd · #13 01-02-2010, 03:02 PM

Thank you all for the pointers on this. I'll use the EPC to take a look at the specifics for this car and see if I can determine where this should go, if it goes anywhere. In the meantime it's far too cold to be rooting around outside and the garage isn't available because of other projects at the moment so I'll just let it go for now.

Thanks again

toomany MBZ · #14 01-02-2010, 03:59 PM

Once on the epc and clicking on an item number a description in the parts list will sometimes result in "line from ____ to ____", I find this very helpful.

mplafleur · #15 01-02-2010, 04:05 PM

Quote:

Originally Posted by glenlloyd

Thanks Nate for providing the image, I believe it is shown in there although the curved U shaped fitting is not shown.

#668 is the small inline filter, #557 is the plastic tube and #534 is the small clip shown at the very bottom in my photo. #609 is not what's at the end of my tube. Perhaps someone has been in there and changed things...incorrectly...don't know.

The big question now is where is the correct #609 fitting and what does #609 go to and what is the function of this vac line?

As a side note the schematic doesn't exactly match up with what's going on near the right headlight. That doesn't mean that my setup isn't correct, just that there is a difference. I don't know whether this is due to someone having taken things apart and then not knowing exactly how it goes back together.

Thanks
Steve A

That's a great diagram. Do you have one for the OM603.961? ('86 300SDL)

Post Script:

Let's see if I can dig one up from that EPC site first...