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 ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-11-2002, 02:37 PM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,278
Unhappy Center air vents

The two center vents in my 85 240d do not seem to supply much fresh air. I do have AC but no climate control. The slider control in my 79 240d really lets a good amount of air in but NOT so on the 85. I have searched the archives without result and am assuming it is a mechanical system w/o the use of vacuum actuators. Could the ducts be plugged or are you just expected to crank up the AC for fresh air? Any advice would be much appreciated Thanks
__________________

1985 Euro 300TD 5 spd 220K
1985 Euro 240D 5 spd 130K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #2  
Old 08-11-2002, 02:44 PM
Registered User
 
Join Date: Aug 2001
Location: Evansville, Indiana
Posts: 8,150
I believe that there is a vac switchover on the 240D that switches from outside air to recirc when the AC is on. If you don't have adequate vac, the flap will stay part way open. This is true if the AC uses outside air, but has a recirc provision. If it is stuck in recirc, you won't get much outside air.

You can test by switching the ignition on, but not the engine, then engage the AC with the temp dial -- if you don't hear the flaps moving when you switch on and off, you either have a vac problem or a bad swith or servo.

You can test in integrity of the vac system by trying to pump down the green line in the engine compartment -- if it won't hold vac on the passenger compartment side, you have a leak. If it works properly with a hand pump suppling vac, you have a vac supply problem or leak in the supply side.

Make sure the slider is actually attached to the flap, too -- I have to manuall open and close the one in the 220D, it's broken off.

Peter
__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
Reply With Quote
  #3  
Old 08-11-2002, 07:32 PM
Stevo's Avatar
Registered User
 
Join Date: Apr 2002
Location: NW WA
Posts: 6,278
Peter
Thanks for the reply. I went out and turned the ignition key as if the engine was running then moved the AC adjustment wheel and there was NO noise as in flaps moving , nothing too be heard. The PO had just spent almost $800.00 on the AC and I was thinking maybe they screwed something up but this switchover thing would be under the dash and they wouldn't have messed with anything under there I think? So what you are saying is that the AC would use this vacuum switchover to bring in outside air (open) or recirculate inside air (closed) and the vent is at least partially closed so when I just want fresh air (w/o AC ) , No can do? I need to invest in a Mity Vac and check out the green line then.

Thanks again for your help
__________________

1985 Euro 300TD 5 spd 220K
1985 Euro 240D 5 spd 130K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote
  #4  
Old 08-11-2002, 08:06 PM
Registered User
 
Join Date: Aug 2001
Location: Evansville, Indiana
Posts: 8,150
I certainly remember some flaps moving when I tested the AC in 1983 240D with manual AC. There is also a lever on the center vents, I think (maybe not) that closes off the outside air. There is on the W115 chassis, but that doesn't mean much.

You should be able to get unconditioned air out of the vents, and if nothing comes out unless the AC is on, I'd suspect the vacuum system. Check to make sure the green plastic line up by the brake booster isn't loose, then get a MitiVac or similar hand pump. Very difficult to apply that much vac by mouth (and not recommended!), but you can also use a pump intended for AC evacuation -- it will be too strong, but at least will let you know if the sytem holds vac. If it leaks down, you will have to look under the dash for the leak. If it works with external vac, you need to find out why you don't have enough.

Peter
__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
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 05:20 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page