how to vent the brakes on a L406DG from 1975? - Mercedes-Benz Forum

LinkBack Thread Tools Display Modes
post #1 of 2 (permalink) Old 04-23-2010, 01:12 PM Thread Starter
BenzWorld Junior Member
Date registered: Nov 2009
Vehicle: Mercedes-Benz 207D
Location: Europe
Posts: 8
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
how to vent the brakes on a L406DG from 1975?

I have a L406DG (probably same as any 406D van) van from year 1975. The van was unused for many years, and now the problem is it was completely out of brake fluid. I refilled the container to full with DOT4, but that is not enough, because as I understand I need to vent the brakes now.

How do I do that? I have a service book about 207D - 407D series, which is a bit newer (after 1982) and the instruction given there is not really helpful. It tells that I need to take off the wheels and there will be some nuts that I need to unscrew and then keep pressing the break pedal until the brake fluid starts flowing through the venting valve. I located the valve but I can't find which nuts/screws/whatever I need to unscrew. My wheels look completely different then on the diagram in the 407D book, and in fact 407D wheels are on 14" rims, and mine are 16". Also when taking off my wheels, there are no nuts/screws uncovered that would not be uncovered without taking off the wheels, so I feel that it is not needed to take off the wheels.

I attached a 6 mm transparent hose to the venting valve and keep pressing the break, but no break fluid flows through the hose. Is there a nut/screw/something I need to unscrew (probably there is) and if then where is it, can someone help me locating the right screw?

I don't want to try unscrewing any random screws there are on the breaks, because I fear the breaks will fall apart and I will not be able to put it back together.

Also does the order of venting the wheels matter? First front/back wheels or doesn't matter?
miernik is offline  
Sponsored Links
post #2 of 2 (permalink) Old 04-23-2010, 01:42 PM
BenzWorld Elite
Govert70227's Avatar
Date registered: Oct 2009
Vehicle: 2000 VW Golf Variant
Location: Leiden, Netherlands
Posts: 2,952
Mentioned: 0 Post(s)
Quoted: 4 Post(s)
The valve itself turns to open it. Use a ring wrench of the correct (metric) size so that you don't damage the valve.
Govert70227 is offline  
Sponsored Links

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode

    Similar Threads
    Topic Author Forum Replies Last Post
    how to vent the brakes on a L406DG from 1975? miernik W901-905 Sprinter 0 04-23-2010 12:32 PM
    Central vent cold air, side vent warm air, help please Benz235 W202 C-Class 6 07-24-2009 11:38 PM
    Mysterious Side vent & Center vent echaocn W210 E-Class 1 04-20-2009 10:04 PM
    Power brakes out- 1975 230 samuiholidayhomes Vintage Mercedes-Benz 3 10-11-2005 05:19 AM
    2003 C230 Sedan brakes to 2004 cross-drilled brakes? aaronmarks W203 C-Class 1 10-05-2005 04:00 PM

    Posting Rules  
    You may post new threads
    You may 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 Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On


    Title goes here

    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome