Testing Vacuum Pods - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
#1 (permalink) Old 04-12-2008, 02:32 PM
BenzWorld Member
 
Date registered: Aug 2007
Vehicle: 82 300D
Posts: 111
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Testing Vacuum Pods

I've been reading alot about how to replace the Vacuum Pods in my HVAC system for an 82 300D. My HVAC system currently always puts air out the defrost and side vents no matter what setting. How do I determine which pods (if any) need to be replaced without actually pulling the dash to replace them?
tgoodwin is offline  
Sponsored Links
Advertisement
 
#2 (permalink) Old 04-12-2008, 06:08 PM
BenzWorld Elite
 
to loss's Avatar
 
Date registered: Nov 2005
Vehicle: 1982 300TDT 150,000 miles 1985 380SE 130,000 miles 1991 560SEL 81,000 miles (a/k/a the nightmare)
Location: Massachusetts
Posts: 1,984
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You'd do best by pulling the dash, and getting replacement diaphragms for your pods through George Murphy at Performance Analysis Company in Tn... (He supplies a sheet that outlines the way to test the pods once they are installed, and the same procedure could probably be used to troubleshoot the vacuum system... but by the description of your problem, sounds like you'd be better served taking the dash out, as I believe you'll find more systemic problems... also, if sometimes it's best to change all relevant and known failure points of the system (within reason and cost effectiveness) at this stage of the game).

While you've got the dash out, you can change all of the rubber bits that will fail sooner or later, and check your vacuum switchover valves and replace. I don't think there is any easy way to diagnose your problem.

"I don't think it's nice, you laughin'. You see, my mule don't like people laughing. He gets the crazy idea you're laughing at him. Now if you apologize, like I know you're going to, I might convince him that you really didn't mean it."

"I love the smell of diesel in the morning... smells like... like victory"

Last edited by to loss; 04-12-2008 at 08:53 PM.
to loss is offline  
#3 (permalink) Old 04-13-2008, 04:56 AM
BenzWorld Elite
 
Gregs300CD's Avatar
 
Date registered: May 2005
Vehicle: 1982 300CD
Location: West Virginia
Posts: 5,004
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
The only pod that you can not easily get to without pulling the dash is the #3 pod that controls the center vents. You can test that one without pulling the dash as well.

http://www.benzworld.org/forums/w123...m-control.html

But if that one is your problem, removing the dash isn't impossible.

Last edited by Gregs300CD; 04-13-2008 at 05:36 AM.
Gregs300CD is offline  
#4 (permalink) Old 04-13-2008, 06:56 AM
BenzWorld Member
 
Date registered: Jan 2007
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It is also possible to change the center vent pod with out pulling the dash.
I just did mine and all it takes is patience and small hands

Tony
tgomes is offline  
#5 (permalink) Old 04-13-2008, 07:52 AM
BenzWorld Elite
 
Gregs300CD's Avatar
 
Date registered: May 2005
Vehicle: 1982 300CD
Location: West Virginia
Posts: 5,004
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I don't think I could do it. Something would break. Not only are my hands way too big to get in there, but frustration level with the dash off is about 80% threshold as it is. I was trying to be careful, but still snapped one of the pegs and broke one of the spring locks in half. I found a suitable replacement for the spring lock at the hardware store and I was replacing the entire pod, so no big deal. Still a royal pain.
Gregs300CD is offline  
#6 (permalink) Old 04-13-2008, 09:13 AM
BenzWorld Member
 
Date registered: Aug 2007
Vehicle: 82 300D
Posts: 111
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
The center pod is the one in the dead center of the dash up close to the fire-wall?
tgoodwin is offline  
#7 (permalink) Old 04-13-2008, 11:27 AM
BenzWorld Elite
 
Gregs300CD's Avatar
 
Date registered: May 2005
Vehicle: 1982 300CD
Location: West Virginia
Posts: 5,004
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Read the post: http://www.benzworld.org/forums/w123...m-control.html

You'll see where they're all located.
Gregs300CD is offline  
#8 (permalink) Old 04-13-2008, 12:01 PM
BenzWorld Member
 
Date registered: Jun 2004
Vehicle: 1980 300D
Posts: 309
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The center vent vacuum actuator is up on top, centered beneath the dash by the air flap it actuates. By removing the circular center vent housings - they unscrew easily from retaining rings inside dash holding them in place - it is possible, though tedious, to replace diaphragm in actuator without removing dash, helped by a third person with small hands reaching through center vent openings to hold things in place. More simple than removing dash, dexterity and patience required. George Murphy's replacement diaphragms work very well, once diaphragms are replaced actuators work flawlessly. New replacement actuators often have different mounting systems than actuators in place - check and double check mounts.
DOUGLAS MARTIN is offline  
#9 (permalink) Old 04-13-2008, 10:08 PM
BenzWorld Extremist
 
FratBoy's Avatar
 
Date registered: Jun 2006
Vehicle: 1980 280CE; 1982 300CD
Location: West coast
Posts: 1,002
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Removing the glove box (easy to do) will also yield access to the center vent actuator. This method may be more graceful than removing the center vents, IMHO...

FB

The Inventory:
1982 300CD 162k (5 speed coming soon)
1982 300SD 180k with 383 Stroker

Those Not so Lucky:
1980 280CE US with Euro M110 + 4 speed 126k, more pics
1980 280CE Euro 4 speed 101k
1983 280E Euro 5 speed (parts only)
1980 280E Euro 4 speed 165k
1985 500SEC US (shmoove)
1982 300D US 4 speed
1978 300CD US
1979 300D US
FratBoy is offline  
#10 (permalink) Old 04-14-2008, 03:43 PM
BenzWorld Member
 
Date registered: Aug 2007
Vehicle: 82 300D
Posts: 111
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
I can't find where to buy the replacement diaphragms. Can anyone help me with a link?
tgoodwin is offline  
Reply

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W123 E,CE,D,CD,TD,TE Class


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

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
HVAC Vacuum Pods from Autohaus or from Dealer? to loss W126 S,SE,SEC,SEL,SD,SDL Class 5 12-10-2007 11:03 AM
ac blower things to check before suspecting vacuum pods St3ve W124 E,CE,D,TD Class 0 11-10-2006 01:11 PM
Need gauge pods DynamicS R171 SLK Class 3 07-19-2006 06:00 PM
Climate control vacuum pods - repair story Niloc W123 E,CE,D,CD,TD,TE Class 2 01-17-2006 12:12 PM
HVAC vacuum pods - part numbers? special tools? kggkgg W124 E,CE,D,TD Class 0 02-26-2005 12:07 PM

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome