Has anyone ever tried to fix/rebuild the climate control servo? - Page 2 - PeachParts Mercedes-Benz Forum

boneheaddoctor · #16 10-08-2004, 02:13 PM

THat link is deserving of a sticky if ever I saw one.

TX76513 · #17 10-08-2004, 04:09 PM

Very Cool site! Like ACC for Dummies :p I actually understood some of it

Mark DiSilvestro · #18 10-08-2004, 10:11 PM

A few years ago, I experimented with the servo on a friend's '79 300D. The AC was shot and he just wanted some kind of heat in the car so his son could drive to school in winter. The only thing working in the climate control was high defrost with no heating. The servo's coolant valve had seeped vapor into the cavity below the motor and turned it and the little gearbox into rusty junk. I removed the rusty machinery and made up a neat little cable operated cam and lever device to replace the servo motor assembly and operate the vacuum valve and fan control. Unfortunately, possibly due to the fried amplifier, my experiment failed. So I bypassed the servo's coolant valve and rigged the cable control to a manual Dodge Omni heater valve. Now my friend still has the high defroster fan, plus a way to add some heat.

Happy Motoring, Mark

boneheaddoctor · #19 10-08-2004, 10:19 PM

Just so its a link that is clickable.

www.imperialclub.com/Repair/Lit/Master/281/index.htm

I bookmarked that. Somebody needs to archive the whole thing for posterity in case that site closes.

#20 10-12-2004, 05:36 PM

I just opened up my AC Servo, and am cleaning up and lubercating everything inside, and sealing the cracks in the plastic. My motor is running just fine, so I hope by doing this, it will work like new after I get everything put back together.

#21 10-12-2004, 10:01 PM

I almost had everything back together, then the little clip that connecets the rod to the plunger broke off. So I had to pull the servo out and take the whole unit apart. I had everything back together once again, and the clip came loose again, so this time I used the pliers to press it together and the top part broke off. I decided I could use some JB weld on the plunger to, and put the little rod into it, I am hoping it will hold together. Tomorrow I will put it all back together once again. Does anyone know where I can but just that little plunger the metal rod and the clip???

#22 10-13-2004, 08:30 PM

My conclusion is that tearing the AC Servo apart, and putting it back together is bad. I had everything working perfect for a short time, then the pressure knocked all the screws loose, and it leaks bad now. I am going to bypass the whole system with some kind of adjustable valve and copper pipe...

boneheaddoctor · #23 10-13-2004, 09:08 PM

Mikemover posted this link in another thread.

( )

A digital solution to a vacume servo monstrosity.

hockeynut · #24 10-13-2004, 09:17 PM

For a measly $350 you can buy a rebuilt unit

Mine has been working great

(i think there is a core deposit also)

boneheaddoctor · #25 10-13-2004, 09:30 PM

Quote:

Originally Posted by hockeynut

For a measly $350 you can buy a rebuilt unit

Mine has been working great

(i think there is a core deposit also)

True but a siezed servo usually fries the amp.............so even more money and how long will it last? its anyones guess. If your servo is cracked adn coolant got in and smoked it , then its not rebuilible and you get no core charge returned to you, as me how I know that.

Its a more reliable in not a slight bit more costly replacement option.

I year ago I would have hopped on it. If mine dies again soon, I still might.

Telecommbrkr · #26 12-16-2004, 12:14 AM

We have recently put our '82 300SD back on the road for winter duty and just a few weeks ago our fan became stuck on high/Defrost only. I do hear the vacuum and the flap or vane or whatever moves insde the heater unit to direct airflow, but nothing changes. Am I to assume that my servo or amp is starting to go down?

Please help my eyes can't take the heat no more!!

#27 12-16-2004, 01:47 AM

Quote:

Originally Posted by Telecommbrkr

We have recently put our '82 300SD back on the road for winter duty and just a few weeks ago our fan became stuck on high/Defrost only. I do hear the vacuum and the flap or vane or whatever moves insde the heater unit to direct airflow, but nothing changes. Am I to assume that my servo or amp is starting to go down?

Please help my eyes can't take the heat no more!!

You won't have an A/C Servo, they were used from 1977-1980...

Jimmy Joe · #28 12-16-2004, 02:56 AM

Quote:

Originally Posted by boneheaddoctor

Somebody needs to archive the whole thing for posterity in case that site closes.

Got it. It is 3 megs total. Anyone wants it emailed, yahoo and hotmail are now supporting these large transfers, just let me know. If it goes down, I will repost it.

Too much to read for me right now. Too tired. I tinkered with mine until I just bypassed it, maybe now I will have the drive to go back and figure it out.

Jimmy Joe · #29 12-16-2004, 03:13 AM

By the way, that thing was printed in 1971. What the heck was MBZ thinking putting that beast of ancient technology into cars ten years later?

I discuss my simple bypass here:
http://www.peachparts.com/shopforum/diesel-discussion/110502-%242-servo-aux-pump-bypass-fix.html#post771037

Kyle Blackmore · #30 12-16-2004, 08:25 PM

Telecombrkr your problem may be a simple vacuum leak , have you been under the dash or hood lately ? I had the same problem when I was installing the stereo in my car , and I unknowingly knocked a vacuum hose off. The climate control vacuum source under the hood is in the brake master cylinder area.