Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 03-28-2016, 02:12 PM
Registered User
 
Join Date: Nov 2015
Location: Los Angeles, CA
Posts: 72
w126 Complete Vacuum tub replacement?

Hi I am considering doing a complete replacement of the vacuum tubing and connectors throughout my 81 300sd w126. Most of the parts look like they are original and honestly I thought this would be a good way to simply examine the entire system and be at least a bit more sure that possible leaks are identified and attended to.

Multiple questions:

1. Am I completely nuts for wanting to do this? (this could very well be the case)

2. Is there a complete vacuum replacement kit or listing of parts that I would need to undertake this?

3. Has anyone done this and if so - was it worth it?


Thanks in advance!!

Reply With Quote
  #2  
Old 03-28-2016, 02:26 PM
Registered User
 
Join Date: Nov 2015
Posts: 687
I've done most of this on my w123 (all of the engine bay and the HVAC system, vacuum locks are probably not going to get touched). Generally, I think that the hard plastic lines are not worth replacing, I'd suggest just inspecting them and checking for breaks.

The rubber lines are a different story. Generally I've been replacing all of these, as well as most of the T/Y/X fittings and adapters. You can get good quality OE Mercedes rubber lines fairly inexpensively - I prefer the style with 2 white stripes on them, I'd get at least 3 meters, maybe even 4 or 5 (not sure how much you'll need on a w126), plus more of the fittings than you think you'll need. Invest in a vacuum pump and learn how to use it, you can isolate and test each system - though I've been having trouble finding test procedures for some elements. I also purchased something like 160 vacuum hose clamps made out of nylon. These can be squeezed in place with a pair of pliers and should prevent hoses from being disconnected in the future. It's not exactly stock, but I got sick of chasing leaks and disconnecting stuff. I bought 5/16" fittings, though I found some of the fittings under the dash could really have used 3/8". I'll let you find a source, if you want to do that.

I've found that once I disconnected an old line, there was a pretty good chance of that line leaking in the future.
Reply With Quote
  #3  
Old 03-28-2016, 05:49 PM
Registered User
 
Join Date: Nov 2015
Location: Los Angeles, CA
Posts: 72
Thanks for the input! All very helpful - will focus on the rubber lines first. Do you know if there are diagrams (mainly for the engine compartment) of the vacuum lines and associated connectors needed? Would be helpful to get a count of the pieces before ordering lol.
Reply With Quote
  #4  
Old 03-28-2016, 05:50 PM
Registered User
 
Join Date: Nov 2015
Location: Los Angeles, CA
Posts: 72
nm quick google search answered my question - Doh!
Reply With Quote
  #5  
Old 03-28-2016, 08:07 PM
Sev's Avatar
Sev Sev is offline
Infractions: 99/99 (999)
 
Join Date: Apr 2007
Posts: 1,461
You're totally normal for wanting to replace 30+ year old brittle vacuum lines that, if accidentally broken due to removing and replacing a vacuum tube, can ruin your car's ability to brake, shift and about a dozen other things. These cars are so vacuum-dependent that it would be crazy not to replace these old parts.

That being said, there is probably a thread on this board that discusses exactly how many meters of vacuum tubing you need, what colors of tubing you need (to match the original vacuum tube colors from MB), where you can get them, and exactly how many and of what type/shape rubber vac tube connectors you need as well.

Have fun doing your vacuum tube replacement. All the seniors on this site have all done it to our cars and we all benefit ted from not having to resort to weird tricks like applying propane to where we think there is a vacuum leak to see if there's a surge in throttle.

Yeah. That's real safe to do in a running car
__________________
i know Jim Smith. i don't actually know him, but I know of him
http://imageshack.com/a/img923/6201/RQ1H6A.jpg
Reply With Quote
  #6  
Old 03-29-2016, 01:35 AM
Registered User
 
Join Date: Mar 2009
Location: San Diego
Posts: 3,067
I would hesitate to replace ALL. Normally, the vacuum tubes underneath the carpet last a long long time. If you are so inclined then I would recommend to replace all rubber connectors under the hood. Those become brittle due to heat and exposure. Check out the vacuum hose in door pillars as they 'move' when opening or closing the doors. They could become brittle and crack. You can also replace all the doors, trunk, gas cap pods if you want.

The air circulation pods could also give you problem if it leaks. Car won't shut down. In other words, the sky is the limit to change out everything.
__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.
Reply With Quote
  #7  
Old 03-30-2016, 12:36 AM
Registered User
 
Join Date: Nov 2015
Location: Los Angeles, CA
Posts: 72
Yes I think I am going to focus on under the hood initially since that seems to definitely be where the most wear and tear is. Start with the rubber hoses, joints and plastic connectors and move into the plastic lines as well as those mostly seem to be approaching 40 years old in the near future
Reply With Quote
  #8  
Old 03-30-2016, 10:22 AM
Registered User
 
Join Date: May 2007
Location: Out in the Boonies of Hot, Dry, Dusty, Windy Nevada
Posts: 9,585
Here are a list of Vacuum info threads.

Mercedes Vacuum diagrams

The Vacuum lines under the hood are about the same between the W123 and W126, except for the door lock system.
The W126 uses a Vacuum Pump in the trunk for the lock system.

Charlie
__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works
Reply With Quote
  #9  
Old 03-30-2016, 01:52 PM
TX76513's Avatar
Platinum Member
 
Join Date: Apr 2003
Location: Brandon, Mississippi
Posts: 5,203
I did my SDL over a period of a month or so. Take a piece off, cut a new piece and put it on - repeat. Its worth it.

__________________
BENZ THERE DONE THAThttp://www.peachparts.com/shopforum/...c/progress.gif
15 VW Passat TDI
00 E420
98 E300 DT
97 E420 Donor Car - NEED PARTS? PM ME!
97 S500
97 E300D
86 Holden Jackaroo Turbo D
86 300SDL
(o\|/o)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 01:43 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page