W116 expansion valve

[Robert Squires]

Does anyone recall whether the expansion valve is located above the gas pedal (300SD, 116.120)? Any tips to make the replacement easier (if that's where it's located)? And, finally, do you know what the factory time allotment is for that job? Thanks.

[300SDog]

Jeeze man, i just found out today the damned steering lock is vacuum controled too. Can ye believe it? Obviously MB went full-tilt boogie for vacuum gear in late '70s with 116. Am surprised they didnt opt for vacuum powered windows.

Wish i knew what yer talkin about with "expansion valve linkage" on 300SD, it kinda scares me. Meanwhile boning my own 116 of silly over-engineered features is definitely on the agenda. The rule with late '70s and early '80 over-engineered deluxe features is trash anything that dont look important. Pull it, hurl it into the woods and replace it with manual gear instead.

I wanna improve my 116 by makin it as manually controled as possible, same as best features of other Vintage MB's. Reconnoitring less is better than more when it comes to vacuum and electrictronic features. If there's such a thing as expansion valve linkage can it be discarded?

[Robert Squires]

* DieselDog, I'm afraid we differ in our opinion of Mercedes technology. When the cars are new you pay a premium price for the research and development, which, in my opinion, is (and should be, for the price) head-and-shoulders above all the rest. That's why, even 20 years later, the cars hold their own very well against the new non-MB offerings. My own MB, a 300CE, is 17 years old now and is still a very "up-to-date" ride. I wouldn't dream of changing a bolt on that car. I want it to be precisely as it was designed, with not the slightest modification. And it's mandatory that everything, repeat everything, works according to spec.
* More to the point though, this 300SD is a client's car and I'm trying to get his AC working the way it should. It's been a long time since I did an expansion valve in a W116 and was trying to refresh my memory. The expansion valve, as you know, is the device which regulates the flow of refrigerant, particularly through the evaporator.

[Mike D]

Unless the car is RHD the expansion valve should be behind and under the glove box.

The receiver/dryer is on the right hand firewall, correct?

[Robert Squires]

Once I took a few things apart, memories of the whole job came back.
The AC expansion valve (in a W116.120, left-hand drive, US export model) is, in fact, located roughly straight up from the gas pedal and forward of the ignition switch. For easier access, remove the under-dash panel as well as the instrument housing. I also unplugged the ignition switch, moving the thick plug and cable out of the way, as well as moving the left-most air duct out of the way in the area of the exp valve. It's maybe a 3 hour job, including refrigerant recovery before the exp v replacement, recharging afterwards, and a coffee break. Thanks to all who read the posts and thought about it.

[Mike D]

Thank you for letting us know. This will save someone time and aggravation.

[wbain5280]

Here's a link to a W126 page with instructions.

http://dieselgiant.com/repairyourac.htm

the 116 and 126's are similar.

[Doktor Bert]

Originally Posted by wbain5280

The 116 and 126's are similar.

Their location is totally different. W116 valve is under dash, above and right of the accelerator pedal on the LHD (U.S. Model) version...Robert

[280EZRider]

Donīt forget to put a good vacuum on the system before recharging.

[Doktor Bert]

Yep. I have a Venturi-Vac that uses shop air pressure to creat a vacuum....

[westchester aut]

thinking about converting my 1979 300 sd 116 body in to grease car.do u thing the car will loose it value once its converted to veg oil burning.Thanks

[compu_85]

If the fuel you're using in the engine begins to affect the air conditioning you've done something very wrong....

Oh you said value not valve. That depends on who is buying.

-J