center vents not working on 560SL - Page 3 - PeachParts Mercedes-Benz Forum

maheath · #31 07-21-2006, 07:52 PM

It's worth noting that if you have an economy gauge in your instrument panel and it's not working, then your center vents are probably not working either. The economy gauge shares the same vacuum source as the climate control system, which is a vacuum line coming out of the back of the intake manifold.

I went through my entire climate control vacuum system, replacing only one non-working actuator. It still wasn't working. The connector on the intake manifold had broken and the end of the vacuum line was just hanging behind my engine. I fixed that and suddenly I have center vents again.

Roncallo · #32 07-22-2006, 09:22 PM

See "Will Sadie Ever Run Again"

Will Sadie Ever Run Again

John Roncallo

fpilot · #33 08-06-2006, 05:19 PM

Hi. I am new to my 1986 SL and like many this summer am needing the ac badly. The center vents just went out on me yesterday. I do not understand why they went out and how the nice cold air is now coming from the defroster (top vents). Also, not sure if I understood on here how to tell if it is a vaccuum leak by turning the car off and seeing how the ac works. I am not one to be able to get in the car and tear stuff apart. I will probably do more damage but I want to understand and be prepared when I take it somewhere. Also, any ideas of anyone in Dallas to take it to?

Thank you all.

Marla

Roncallo · #34 08-06-2006, 08:09 PM

Quote:

Originally Posted by fpilot

Hi. I am new to my 1986 SL and like many this summer am needing the ac badly. The center vents just went out on me yesterday. I do not understand why they went out and how the nice cold air is now coming from the defroster (top vents). Also, not sure if I understood on here how to tell if it is a vaccuum leak by turning the car off and seeing how the ac works. I am not one to be able to get in the car and tear stuff apart. I will probably do more damage but I want to understand and be prepared when I take it somewhere. Also, any ideas of anyone in Dallas to take it to?

Thank you all.

Marla

It sounds like you may have lucked out. In my case I had air out the side vents only not sure about the defrost nozzeles. I had to remove the dashboard and evaporator/heaterbox to replace the center vent vacume actuator. Of course while I was there I also replaced the legroom actuator. All of the other 5 actuators can be fixed without removing the dash.

I'm not shure about the turning off the car idea. I guess that would imply that there is a check valve and if you turn off the car, turn the key back to the run position and air remained blowing out of the correct vents the actuators and check valve could be assumed to be working. My thoughts on this would be that only the active actuators could be checked this way and if you had a leak you would not know if it was an actuator or check valve or which actuator. A vacume pump applied to each actuator is the only shure method.

I would also advise that if your dashboard was in good condition you may not want to remove it because the removal of the dashboard is somewhat stressfull to the old vinal and a vinal crack is likely.

Good Luck
John Roncallo

fpilot · #35 08-06-2006, 10:46 PM

Thank you Roncallo. More questions: You said all of the other 5 actuators can be fixed without removing the dash. How does one fix them w/out going into the dash. My dash does have a small crack in the center closest to the windshield. If the dash does not have to be taken off then I would prefer to not go that route. I looked through the old records for this car. I bought it this January. I know the previous owner had problems with the ac before but not sure what all was involved. Can see in 2005 the relay switch was replaced as well as the control head. My economy gauge works fine, someone mentioned that on a reply to this thread and they said it was the same vacuum. What else could be wrong for the center vents to not pull the air through. I am getting the side vents to work with cold air.

Thank you all.

Marla

lynns · #36 08-06-2006, 10:53 PM

Quote:

Originally Posted by fpilot

Hi. I am new to my 1986 SL and like many this summer am needing the ac badly. The center vents just went out on me yesterday. I do not understand why they went out and how the nice cold air is now coming from the defroster (top vents). Also, not sure if I understood on here how to tell if it is a vaccuum leak by turning the car off and seeing how the ac works. I am not one to be able to get in the car and tear stuff apart. I will probably do more damage but I want to understand and be prepared when I take it somewhere. Also, any ideas of anyone in Dallas to take it to?

Thank you all.

Marla

Marla,

Please consider finding a Independent that will check your vacuum system for about $85. After they determine where your problem is you can then decide if you trust them and want to pay the cost of ther suggested repair. You may need to go to several Independents and ask them what it would cost to replace just the center vent actuator. This is usually what needs to be replaced if the center vents are not working. If they tell you it will require that they remove the dash leave and go somewhere else. The center actuator can be fixed by going threw the radio/climate control area of your center consol. It is difficult but can be done. I paid an Indy $450.00. Or you can go to a Dealership and pay an arm and a leg (approx. $1,700.00+) but be pretty much garanteed.

fpilot · #37 08-06-2006, 11:05 PM

Thank you Lynns. I will do as you suggested. I still have not found a garage I trust but will keep trying and will have someone check out the center vents. Glad to know it can be done w/out taking out the dash. And hopefully I will be so lucky too and not be spending $1300. Thank you again! I am hoping to take it in next week when I will be in Northern Cali for the Concours. Marla

lynns · #38 08-07-2006, 12:56 AM

FWIW, here is the name of an Idependent in SoCal that did my center acuator via the radio/climate control openings w/o removing the dash.

Renato Benz Service
27822 Aliso Creek, C-160
Aliso Viejo, CA 92656
949-360-0154

fpilot · #39 08-07-2006, 07:27 AM

Thank you Lynns. I appreciate it but I will have to take my car somewhere here in Dallas, TX. But if I need to call you shop, I will do.

Thank you again.

Marla

Roncallo · #40 08-07-2006, 06:08 PM

Quote:

Originally Posted by fpilot

Thank you Roncallo. More questions: You said all of the other 5 actuators can be fixed without removing the dash. How does one fix them w/out going into the dash. My dash does have a small crack in the center closest to the windshield. If the dash does not have to be taken off then I would prefer to not go that route. I looked through the old records for this car. I bought it this January. I know the previous owner had problems with the ac before but not sure what all was involved. Can see in 2005 the relay switch was replaced as well as the control head. My economy gauge works fine, someone mentioned that on a reply to this thread and they said it was the same vacuum. What else could be wrong for the center vents to not pull the air through. I am getting the side vents to work with cold air.

Thank you all.

Marla

The other five actuators can be done by removing the instrument pannel radio, forward console and glove box. A lot simpler than removing the dash. you will also have to pull these components to do a vacume check on each actuator. The center dual stage element is still a bit tricky to do without pulling the dash but doable.

Other things that can cause this are vacume lines and fitting leaks, a bad vacume switching valve and possibly the AC push button assembly. Vacume actuatores are the most likely.

John Roncallo

fpilot · #41 08-07-2006, 09:26 PM

Thank you Roncallo. I am going to call around some shops tomorrow and see how they would go about finding the problem. I appreciate the info and now I am more educated and can talk decent shop talk with them pertaining to my problem.

Marla

JPMOSE · #42 08-09-2006, 02:49 PM

Maria,

Call Will at S&S Imports in Dallas. He has a great reputation with earlier SL's and hopefully works on the W107 (1972-1989) models as well. Here is his information:

S&S Imports
3303 Wendy Lane
Dallas, TX 75124

214-826-5977

I just had this problem on my 560SL and it was the Defroster Vacuum Actuator, which has dual vacuum lines on it. One of the lines (the "short run") is shared with the line for the Center Flaps Vacuum Actuator. The Defroster actuator is known to be weak and may be the culprit. Mine was replaced without removing the dash. For a quick fix, the line to the "short run" can be blocked off, which will provide vacuum back to the Center Flaps Vacuum Actuator only. In my case this worked until I was able to have the Defroster Vacuum Actuator replaced.

Good luck!

fpilot · #43 08-10-2006, 12:13 AM

JPMOSE, That is awesome! Thank you for the info. Did you have your's repaired at S&S Imports? I called 2 places yesterday and both want at least $1200 just to remove the dash and they said it was the only way to repair it. I prefer not to mess with the dash if it is not needed. Thank you again and I will call S&S tomorrow. I will let you know.

Marla

JPMOSE · #44 08-10-2006, 08:26 AM

Marla....no I had mine fixed at Auto Benz in Marietta, GA. I have heard about S&S Imports through the Pagoda website (230/250/280SLs) and heard good things about Will. I used to live Fort Worth, but now back in Atlanta.

Hopefully, your car just has a vacuum leak or something simple.

By the way, my 560SL was converted to R134a and blows 42dF out of the center vents on a 95dF and humid day....just as a point of reference.

fpilot · #45 08-10-2006, 09:04 AM

Thank you JPMOSE. I will check out S&S and hoping it is simple.

Marla