Vacuum problems in my "new" 1980 300SD

[Mal Kapwn]

Hello all,
I'm new to Mercedes and new to this forum. I recently found two 1980 Mercedes-Benz 300SD's for sale and couldn't pass up the opportunity to own such a cool car. I was told there was very few things wrong with one and that the other was a parts car.  After fooling with the one that runs for a bit, I've noticed that the a/c, heater and door locks don't work. All of this is vacuum related, so after chasing down vacuum hoses I have found a part that is cracked. I've been looking all over the net trying to find out the name of this part, and I can't find it. I'd like to either patch the crack or, preferably, replace the part, but I need to know what it's called. It has vacuum hoses and at least one water line that runs out of it. Any help would be greatly appreciated. This is under the hood, in the back corner on the passenger side.
Thanks!

-Mal

[Mal Kapwn]

Here is a better picture at a better angle.

[jbrasile]

Mal,

This is the a/c servo which controls your entire Climate Control and is notorious for cracking and rendering the a/c/heating system useless. I believe the best approach would be to replace it with a unit from Performance Analysis, they rebuild them using an aluminum housing that in theory should last indefinitely. www.performanceanalysis.com

As for vacuum leaks...  you need to be very methodical and test system by system. First thing to do is buy a vacuum tester such as a Mittyvac. You start by running a series of tests on the lines in the engine compartment in order to isolate the problem areas.

There is a lot of info posted in the Forum on the subject.

Tks

Joe

[spacecommander]

Website link: http://www.perfanalysis.com/
I'd try JB weld first 

[John Hubertz]

Those replacement servos are quite pricey at around $500 each I believe - but you do see them occasionally on eBay.

[ckamila]

The replacement servos are not cheap, but if they fail in the first year another one is shipped out free of charge. After the one year if the unit fails cost is $100.


From the pictures, climate system has plumbing shutoff valves installed which can get you buy depending on your climate conditions. I tried mine this way....PITA but for under $20 you can heat!




chris