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 09-27-2006, 01:51 PM
Registered User
 
Join Date: Nov 2005
Location: Iowa City, IA
Posts: 1,647
Post W123 Automatic Climate Control Repair -- The Easy Way

After putting in new AC, I was ready to get my vents to operate as I wanted and fix the heat always on problem. Regarding vents I wanted -- center vents and foot vents open and defrost off or on as needed.

1) Constant Heat aka Monovalve fix -- unplug monovalve, put in a 3/4 " pex barbed ball valve from Lowes (12.00 after tax) in place of auxillary heater pump that is probably broken. This fits right in existing hoses. If you motor works, sell it to someone in the arctic who may actually need it. This 12.00 ball valve eliminates over $300 worth of broken or soon to be broken parts and is dependable.

2) Defrost venst always on: My defrost vacuum pod leaked (and i was not getting vacuum there anyway so rather than repair that flawed system I put a 5/8 ID gates rubber heater hose in defrost channel on dashboard (you can hardly tell its there) to block off air ducts. I need a good way to hold it tightly down yet still be eaily removable. A better solution may be pending (a pulley and wire and handle to manually operate the defrost). Costs about 14.00 for 5 feet of hose ot Oreilley's.

3) Middle vents won't open--
Remove glove box (pull little platic holder tab things with screwdriver, pull light, pull out glove box
reach back and pull rubber boot ducting on middle vents to get at the flap inside
hold open flap, remove metal arm that connects flap to vacuum pod from the flap side (Its the thing that actually opens and closes flap from flap. it just slips off of a pin on the flap. Its easy. Just do it.)
bend metal arm over the flap to permanently hold it open (This is an insiders secret )
Now you can open and close middle vents manually by twisting vent.

4) Floor vents
I just pushed the flap on drivers side all the way open and it stayed. I may have gotten lucky. That also opened passenger side. I live with these always open.

5) Important -- Disconnect all vacuum lines from pods you no longer use and cap the lines.

Enjoy manual vent and heat control and simpler vacuum system.

__________________
What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius
Reply With Quote
  #2  
Old 12-13-2006, 01:21 AM
Registered User
 
Join Date: Jul 2004
Posts: 105
what do you fix when 10 mins into driving the car the main air flap closes and won't reopen in any setting except AC/Cold ? ? ? I need heat! Fan runs but vents close = suck
__________________
1984 300D "Brown (and Blue) Betty" Over 200k but the odometer isn't counting
Reply With Quote
  #3  
Old 12-13-2006, 06:21 PM
Registered User
 
Join Date: Jan 2006
Location: Temecula CA
Posts: 70
Well, I'll be....

Dunno why I didn't think of that ....
__________________
78 300d 158k driver
80 300d 200k fixer
80 300d parts car
98 Cherokee 240k

" I know for certain that someday while parking or un-parking my Jeep Cherokee, I'm gonna' either pull the headlight switch right outa' its dashboard OR stomp its hood release lever clean offa' the kick panel. It's just a matter of which will happen first."
Reply With Quote
  #4  
Old 12-13-2006, 08:30 PM
W123x3's Avatar
Joe Myers
 
Join Date: Dec 2004
Location: Alabama, near Birmingham
Posts: 46
Questions on Item #1.
Do you open and close the new valve based on need for heat? Are you removing monovalve or just unplugging electrical connection? Does the thermostat still regulate temperature?
__________________
Joe Myers

'83 300D (light blue)
'82 300TD (off white - parked)
'87 300SDL (silver)

'75 300D (black - sold)
'76 300D (beige - totaled by pizza delivery car)
'82 300D (metalic blue) sold
Reply With Quote
  #5  
Old 12-13-2006, 08:40 PM
JimmyL's Avatar
Rogue T Intolerant!!!
 
Join Date: May 2004
Location: Sunnyvale, Texas (DFW)
Posts: 9,675
I can see maybe jacking with the vent situation, but the monovalve repair kit is very easy and not expensive....
__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John
Reply With Quote
  #6  
Old 12-13-2006, 08:45 PM
W123x3's Avatar
Joe Myers
 
Join Date: Dec 2004
Location: Alabama, near Birmingham
Posts: 46
My impression is that the aux pump is only needed to boost flow at idle. So maybe a straight through connection would suffice in most cases. Does anyone know if the aux pump reduces flow if it is not working?

The manual changes to the flaps sounds promising.
__________________
Joe Myers

'83 300D (light blue)
'82 300TD (off white - parked)
'87 300SDL (silver)

'75 300D (black - sold)
'76 300D (beige - totaled by pizza delivery car)
'82 300D (metalic blue) sold
Reply With Quote
  #7  
Old 12-13-2006, 09:45 PM
ncof300d
Guest
 
Posts: n/a
Aside my three Merc's I have had several Buicks and Cadillacs with climate control. I HATE THE @#$^@@%@ things. Just give me a fan switch, temperature knob and vent control!!!!!
Reply With Quote
  #8  
Old 12-13-2006, 11:48 PM
Registered User
 
Join Date: Dec 2005
Location: Texas Hill Country
Posts: 510
Item #3...may be easy if you hands the size of a 4 year old little girl! I thought it was very tight back there...but I was try to re-attach the metal strip to the vac pod.

What I wound up doing was using a long screw driver to hold the flap open...then on the right hand side down by the glove box you will see a little white "button" which is actually the flap's pivot point....Super Glue it! Has the same effect...lots of cold air outta the center vents. In fact I think you can do this with out even taking the glove box out (much less removing the whole dang dash!).
__________________
Mark
1983 300TD Wagon
Even a broken watch is right twice a day
Reply With Quote
  #9  
Old 12-14-2006, 10:23 AM
mplafleur's Avatar
User Friendly
 
Join Date: Sep 2001
Location: Lathrup Village, Michigan
Posts: 2,939
You can get a replacement monovalve kit for $20 and replacement rubber diaphrams for the pods for $5 a piece. How much cheaper can you get?

Then the system works great. No hassles.
__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Reply With Quote
  #10  
Old 12-14-2006, 10:39 AM
R Leo's Avatar
Stella!
 
Join Date: Mar 2003
Location: En te l'eau Rant
Posts: 5,393
Quote:
Originally Posted by mplafleur View Post
You can get a replacement monovalve kit for $20
Maybe once upon a time they were $20 but they ain't no more:


Quote:
Originally Posted by FastLane
R3023-15174 Mono Valve Repair Kit Bosch IN STOCK $63.65
__________________
Never a dull moment at Berry Hill Farm.
Reply With Quote
  #11  
Old 12-14-2006, 06:23 PM
Diesel Giant's Avatar
Registered User
 
Join Date: Oct 2004
Location: Loganville/Atlanta
Posts: 2,156
Quote:
Originally Posted by W123x3 View Post
My impression is that the aux pump is only needed to boost flow at idle. So maybe a straight through connection would suffice in most cases. Does anyone know if the aux pump reduces flow if it is not working?

The manual changes to the flaps sounds promising.
Yes the pump flows fine if it is not working, but believe me at idle on a cold morning sitting in traffic, that aux pump is really nice! Beats sticking it in neutral and reving the engine to increase the coolant flow.
__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair
Reply With Quote
  #12  
Old 12-14-2006, 09:36 PM
mplafleur's Avatar
User Friendly
 
Join Date: Sep 2001
Location: Lathrup Village, Michigan
Posts: 2,939
Quote:
Originally Posted by R Leo View Post
Maybe once upon a time they were $20 but they ain't no more:
I bought one last month for $20.

Easy to find on eBay.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

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 07:06 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