HELP! Center Vents Do Not Blow AIR! - PeachParts Mercedes-Benz Forum

Abadjay · #1 09-30-2008, 10:33 AM

I have an '83 SD and an '87 SDL with both cars blowing little or no air on only the middle / center vents

. Is there any easy way to fix this without having to remove the dashboard? The directions on the threads I've seen here look hard and the 300SDL that I have could be ruined with all the electrical parts.

I also noticed that the rear center vent only blows cold air in times of cold. Is there any way to get heat to those vents?

HELP!

Jeremy5848 · #2 09-30-2008, 12:40 PM

The front center vents work only for cooling, not for warm air – as designed by Mercedes. Many of us feel that was an error; Mercedes changed the design in later cars (W210, for example) that can blow warm air from the center vents.

If the center vents do not blow air at all, their vacuum pod is probably broken. You can test the pod with a Mityvac. Replacement of the pod requires pulling the dash – not an easy job. As an alternative, the vent can be jammed open so you always get air (warm or cool) out of it.

The rear center vents are for cool air only. Warm air for the rear seats is ducted in under the front seats. You should be able to feel the warm air coming out when the ACC is set to blow heat. If the floor under the front seats is all jammed up with old papers and dirt, the heat may not be able to get out.

Jeremy

Abadjay · #3 09-30-2008, 05:21 PM

So this means that I have to remove the dash in order to find the problem as to why there is little or no air coming out of the center vents? It couldn't be a vacuum problem outside of the car...perhaps near the vacuum pump?

Jeremy5848 · #4 09-30-2008, 06:18 PM

Remove the glove box and you will find behind it a vacuum manifold. Remove each line and test with a Mityvac. Any that won't hold a vacuum have a bad vacuum pod at the other end of the line. A couple of the pods can be replaced without removing the dash but not all. Sorry.

Abadjay · #5 10-01-2008, 03:31 PM

Do I have to buy this Mityvac somewhere?

Simpler=Better · #6 10-01-2008, 07:16 PM

Yes, and from what I've heard it's totally worth it. It's on my Christmas list

ds190 · #7 10-01-2008, 10:44 PM

Just bought one from Harbor Freight Tools. Need to check the AC vacuum vent pods.

Abadjay · #8 10-02-2008, 12:56 AM

Quote:

Originally Posted by ds190

Just bought one from Harbor Freight Tools. Need to check the AC vacuum vent pods.

I actually live close to a Harbor Freight in West Hills CA. Do you know what it exactly is? Is it around $20?

Jeremy5848 · #9 10-02-2008, 01:22 AM

"Mityvac" is a brand name, Google it. You can buy knock-offs, I'm sure. There are metal and plastic versions, metal is better, plastic will work. There are vacuum-only versions and vacuum plus pressure versions; the latter are mode useful but vacuum-only is less expensive.

SD Blue · #10 10-02-2008, 11:47 AM

Center vacuum pod replacement doesn't require removal of the dash on the W126. But it probably is the trickiest to repair on the W126. It's located behind the pushbutton unit and a search will point out several posts with hints, such as using hemostats, to make it easier.

redassag00 · #11 10-02-2008, 05:17 PM

I know you're enthusiastic about getting help from everyone here, but you can try to search first before you make a whole bunch of posts about problems that have been hashed before....

http://www.youtube.com/watch?v=T6BTcEwtmZo

Heres some threads about W126 Pods.
SDL HVAC vac pod locations? or diagram?

87 300sdl a/c

vacuum pod question?

Yet another w126 climate control probelm!

ACC vacuum questions 85 300 SD

Abadjay · #12 10-02-2008, 06:07 PM

Well then sorry to be frustrating you guys.

Abadjay · #13 10-02-2008, 08:17 PM

http://cgi.ebay.com/Lincoln-Mityvac-Hand-Vacuum-Mity-Vac-Model-06203_W0QQitemZ310089052628QQcmdZViewItem?hash=item310089052628&_trkparms=39%3A1|66%3A2|65%3A15|240%3A1318&_trksid=p3286.c0.m14

Should I get this?

redassag00 · #14 10-02-2008, 09:41 PM

Quote:

Originally Posted by Abadjay

Well then sorry to be frustrating you guys.

We're not frustrated my friend, we've all been there, several times, some of us, and instead of waiting for us to answer, searching will reveal 98% of the answers.

As far as that mighty Vac goes, the auto parts stores sell them for around 30 bucks or less.

mplafleur · #15 10-02-2008, 11:25 PM

Quote:

Originally Posted by Jeremy5848

The front center vents work only for cooling, not for warm air – as designed by Mercedes. Many of us feel that was an error; Mercedes changed the design in later cars (W210, for example) that can blow warm air from the center vents.
Jeremy

I love the old feature and hate the new ones. I have '98 ML and I hate the vents. You cant' turn off the center vents. They are on ALL the time and I can't get fresh outside air from them. I hate warm air blowing on my face and I can't stop it.