DETAILED Under Hood Pictures of '85 300D Vac lines. Any '85s in Rochester, NY? - Page 2 - PeachParts Mercedes-Benz Forum

Dee8go · #16 11-30-2007, 10:03 AM

Quote:

Originally Posted by Brian Carlton

They are a combination of plastic (referred to as "Tecalan") and rubber. Plastic for the long runs and rubber for the connections.

Do they typically fail at a certain point, so many years after they are installed? How difficult would it be if you wanted to replace them?

Brian Carlton · #17 11-30-2007, 10:10 AM

Quote:

Originally Posted by Dee8go

Do they typically fail at a certain point, so many years after they are installed? How difficult would it be if you wanted to replace them?

The rubber turns to "mush" if there is contact with any oil or it cracks after 20 years.

The Tecalan lines turn very brittle so that they'll snap if you look at them funny.

You can get the 4mm Tecalan line and the proper rubber hose on this site or from the dealer. Avoid the McParts hose..........the diameter is not proper.

Dee8go · #18 11-30-2007, 10:16 AM

How hard is it to replace them? Are they somewhat accesible, or are they buried way down inside the car for the most part?

Brian Carlton · #19 11-30-2007, 10:39 AM

Quote:

Originally Posted by Dee8go

How hard is it to replace them? Are they somewhat accesible, or are they buried way down inside the car for the most part?

The lines for the transmission vacuum control are all accessible. The lines for the vacuum operated locks and the HVAC system are not.

Dee8go · #20 11-30-2007, 11:05 AM

So, replacing them all would be a pretty major undertaking? I hate to think there is something like that just waiting to fail, if there's anything I can do to preempt it.

Brian Carlton · #21 11-30-2007, 11:14 AM

Quote:

Originally Posted by Dee8go

So, replacing them all would be a pretty major undertaking? I hate to think there is something like that just waiting to fail, if there's anything I can do to preempt it.

It's too much work to preempt the failure of the lines to the doors or the HVAC. These lines are usually undisturbed and are hidden from oil and elements to a large degree. It's the underhood lines that take the abuse.

A failed vacuum line affects control of the transmission.........nothing more.

What you should do, if it hasn't been done, is to remove all the superflous lines that control the EGR. Simplify the underhood environment and get rid of the leak potential, in addition to eliminating the EGR.

Dee8go · #22 11-30-2007, 11:18 AM

Okay, thanks.

Brian Carlton · #23 11-30-2007, 11:20 AM

Quote:

Originally Posted by Dee8go

Okay, thanks.

.......you need help with that.........

chetwesley · #24 11-30-2007, 11:27 AM

Quote:

Originally Posted by Brian Carlton

...........there goes 30 minutes of work for nothing..........that's why I asked the question originally............

I guarantee it will be useful for other people searching the forum in the future.

635CSi · #25 11-30-2007, 12:58 PM

Now how would I go about eliminating all the BS in a 85 300SD?

Dee8go · #26 11-30-2007, 01:21 PM

Quote:

Originally Posted by Brian Carlton

.......you need help with that.........

People who know me well have said the same thing, . . . "Boy, Dee8go, YOU need HELP!"

. . . . . funny

charmalu · #27 11-30-2007, 01:45 PM

I know this post is about Vacuum lines and so fourth. Plastic does
get brittle under the hood from heat and age over time and can snap,
crack, & pop.

there are three plastic fuel lines to and from the spin on fuel filter
that can be of a concern. if they are dark brown as mine were/are
they are brittle. snapped off one with little effort. amazed at how
soft an pliable the new one is.

Thank you Brian for the detailed description on the 85 spaghetti bowl
under the hood. I will print that for future info.
I did this to my 85 several years ago before I knew of this forum, made
a big improvement on how the car runs.

wish I knew of this forum 10 yrs ago.

Charlie

Brian Carlton · #28 11-30-2007, 02:08 PM

Quote:

Originally Posted by 635CSi

Now how would I go about eliminating all the BS in a 85 300SD?

The '85 SD has the same configuration as the W123 of the OP. Just follow the instructions and the vacuum diagram that I posted above.

Brian Carlton · #29 11-30-2007, 02:09 PM

Quote:

Originally Posted by Dee8go

People who know me well have said the same thing, . . . "Boy, Dee8go, YOU need HELP!"

. . . . . funny

OK, follow these instructions........exactly:

3 vacuum lines 5 holes, help or picture please

SGT John · #30 12-05-2007, 07:30 AM

Not even counting the one that is used for the boost, I appear to have 2 switchover valves... (well... had) They were both in the same area, both were connected to a wire, and were both connected by separate vac hoses to the main vacuum line... Did I pull out one of the parts that DO make your car explode? What did I remove?

the first one is P/N 001 640 7197
the second one I was barely able to read, but after some WD 40 and my wife's toothbrush... (just kidding, I didn't use WD-40) 001 540 70 97

Quote:

Originally Posted by Brian Carlton

1) Find item #84, the vacuum converter. You're going to pull all the vacuum lines and toss it in the garbage.

2) One line from the converter goes to item #60, the EGR valve. Remove this line and toss it.

3) One line goes to the vent filter, item #85. Remove this line and toss it.

4) Remove the line from the vent filter to to item #81, the switchover valve, and toss it.

5) Remove the Y connector and the vent filter and toss 'em.

4) Now, you've got an open Y connection at the vacuum control valve. Remove the Y connector and toss it. Connect the one remaining vacuum line (the vent line) to the vacuum control valve (where the Y was previously connected).

5) The one remaining line to the converter is the vacuum supply line. It comes from item 63, the vacuum orifice. Remove this line and toss it.

6) Plug the open Y connection just downstream of the orifice (or remove the Y connector completely and connect the remaining two lines).

7) Find the line from item #81 to item #71 and toss it.

8) The remaining line to item #81 is the supply vacuum. Remove this line and toss it. However, you'll need to plug the opening at the main vacuum line where this line was connected.

9) Pull out item #81 and toss it.

Now, don't we have a much cleaner engine compartment?

And, no, you don't have to worry that the loss of any of the aforementioned devices will cause your engine to explode.