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 > Vintage Mercedes Forum

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 10-26-2019, 09:01 AM
Registered User
 
Join Date: Jun 2013
Location: Nebraska
Posts: 58
W108 adventures

I bought my 280SE four years ago knowing nothing about classic Mercedes. Thanks in part to this forum (many thanks to the members willing to share their knowledge) and my MB shop manual, I think I finally have it running well. I made the Pertronics conversion but found so many more things wrong. This included a locked up mechanical advance in the distributor, and a leaking distributor vacuum actuator.

I then started looking into the AAV and found it was not even closing half way. A wrench on the hosed proved it would make a difference when functioning as intended. I looked for a replacement but decided on trying the Tomguy bulb squeeze instead. What the hell, I own a vice. It worked, and made a difference when starting the beast. However, it does not completely close off. I can still hear air bypassing so should it close 100%? Vice it again?

Second question. I recently read a reply from Graham that he sets his timing at 6 degrees BTDC with vacuum connected. I set mine at 6 degrees with the vacuum line removed and plugged. Did I read this correctly? Apologies for the long post.

__________________
Ron
1972 280 SE 4.5
2017 Lexus ES 350
2011 Ford Escape
2006 Chevy Silvarado
Reply With Quote
  #2  
Old 10-28-2019, 12:22 PM
Registered User
 
Join Date: Oct 2012
Posts: 21,827
These should close off 100%. I like to remove them and boil them in a pot of water. Then, using a pair of pliers, I pick them up, slip on the hose and blow through the hose. If I can blow at all I know it will not work as planned.

But if only a tiny bit of air gets through then, yeah, they will work OK. Or at least until you can find a good one.

The vice squeeze thing will only take you so far. When these are new the bulb is smooth. When they are rebuilt by the factory you will see four indentions running up the side of the bulb. This is where the rebuilders put the squeeze on it.

The early ones can be rebuilt but it is a major process. There are instructions on line where others have done it. The later models cannot be rebuilt, or at least I have never heard of anyone doing it.

You can also boil them and hold a strong small flashlight up to one of the holds and look through them. Do this at night and have someone flip off the lights in the room. Then hold the bolted valve up, holding the hot valve with the pliers, and shine the light through one side and look into the other. If you see any light they are leaking. You should see total darkness.

This prevents you from having to blow through it. Even with the hose attached and blowing through it they are still hot and rather close to your face.
Reply With Quote
  #3  
Old 10-30-2019, 06:11 AM
Registered User
 
Join Date: Aug 2019
Posts: 949
the most important timing angle is measured at 3000 rpm vacuum disconnected (simulating full load) because that's when if you have wrong timing you can do damage, don't worry about idle timing.

I think it should be between 18-22 degrees (3k vac discon.) for a 1972 us model M117 engine

page 2 of this pdf has more info:

https://www.startekinfo.com/StarTek/outside/11883/PROGRAM/Engine/107/M117_45/075-500.pdf

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 06:04 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page