Author Topic: Vacuum lines for climate control  (Read 77 times)


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Vacuum lines for climate control
« on: 07 October 2021, 09:55 AM »
Got my new car in August however the AC doesn't work and as a Houstonian that isn't going to cut it if I want to use this as a daily driver. The defrost is working but none of the other options. When I took a look at the vacuum lines I notices some were not even connected anymore. Any recommendations on a kit to help get the lines attached to the climate control unit? I could use a diagram or a video on how to attach it properly too. I haven't had any luck finding an old Mercedes mechanic so if there are suggestions for that I would greatly appreciate it too. Also, I need to get R12 but might convert instead. I had a friend say to avoid converting. I'd appreciate some input there. Thanks in advance.
1979 300sd Turbo Diesel


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Re: Vacuum lines for climate control
« Reply #1 on: 07 October 2021, 11:39 AM »
There is no kit or video on something like this.  And yes, converting to R-12 will yield a disappointing result.  Even with R-12 the A/C on a W116 isn't all that great.  It's cold enough, but doesn't blow hard enough and takes 20-30 minutes to bring the cabin temperatures down to a comfortable level.  They're not a car you want to drive on a hot Texas summer day. 

Below is a picture of all of the vacuum line routing and what they connect to.  If you're going to wrench on your car yourself it would be very beneficial to you to acquire a climate control manual, an engine manual, and a body and chassis manual.  Some of the mechanical literature is here on this forum, too.
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Re: Vacuum lines for climate control
« Reply #2 on: 07 October 2021, 11:50 AM »
I am using r290 (propane) in my car. It works exceptionally well even in 100f day. The AC system in this vehicle is a nightmare of spaghetti tubes. All waiting to have a couple dry rot and leak. Good luck.