A/C parts interchange question W126 - PeachParts Mercedes-Benz Forum

MS Fowler · #1 08-06-2011, 07:07 AM

I have an '82 300SD and am preparing to install a new A/C compressor, dryer, and orifice tube. I read that '84 and later W126's used a more efficient condenser that had smaller tubes, along with a better electric cooling fan.
Is that true?
Is the condenser and fan a direct replacement, or will I need to change other parts, too?

280EZRider · #2 08-06-2011, 05:07 PM

I don't know that's true or not, but it shouldn't make any difference as far as reconnection is concerned. The fittings will be the same size.

Matt L · #3 08-06-2011, 05:26 PM

Orifice tube? Do you mean expansion valve?

engatwork · #4 08-06-2011, 05:35 PM

Going on memory I don't think there would be any issue installing an '84 condenser/fan in an '82. Not sure if it is an improvement or not.

MS Fowler · #5 08-06-2011, 05:36 PM

Quote:

Originally Posted by Matt L

Orifice tube? Do you mean expansion valve?

Yes

Matt L · #6 08-06-2011, 05:42 PM

Quote:

Originally Posted by MS Fowler

Yes

Not trying to be confrontational, and of course everyone knew what you meant. I just didn't think that M-B used orifice tubes then (and was quite willing to be wrong about it).

MS Fowler · #7 08-06-2011, 07:05 PM

No problem. I "mis-spoke". Lets be correct.

ashedd · #8 08-06-2011, 09:02 PM

Go to the diesel section and ask. I thought the '85 SD's had the parallel flow condenser. The newer fan will work. You may have to be a little creative, but it should all fit. Run R-12 through that PF condenser and make ice cubes!

Don't forget to clean the evap.

compu_85 · #9 08-06-2011, 11:57 PM

Quote:

Originally Posted by ashedd

I thought the '85 SD's had the parallel flow condenser.

Nope it's still tube and fin, but it's an improved design.

-J

ashedd · #10 08-07-2011, 12:48 AM

Then he wants an SDL maybe.

I am trying to keep my MB "knowledge" to 124's.. hard to keep it all straight.

compu_85 · #11 08-07-2011, 02:03 AM

SDLs are fin and tube as well. Some factory R134a vehicles are too, my friends 2003 F350 is.

-J

Hit Man X · #12 08-07-2011, 05:13 AM

Well my 10/84 build 300SD has the updated style condenser and larger aux fan from the factory. BMW also did this around late '85 for their E23s due to lame cooling.

ALSO late 617s received a different water pump pulley, smaller in diameter to overdrive it, so it not only cools the motor better but also spins the fan faster moving more air... making the A/C work better. I think this started in '83, but do your own research on this.

MB also changed the main cooling fan, mine came with the plastic fan as opposed to the earlier aluminum fan. I think the earlier fan cools better as it is on the V8 models as it simply moves more air. I would take a wild guess MB installed this along with the 2.88:1 diff in 1985 to maximize fuel economy from the 617 and free up a bit of power.

I would like to install the earlier fan for more airflow for A/C at low speeds due to my climate.

pmckechnie · #13 08-07-2011, 09:07 AM

Before you buy a condenser, check to make sure it will work. Most would think that a 126 is a 126 but that doesn't apply here. There was several changes in hoses, compressors,fans, condensers, etc over the years and the gas and diesels were different. Just use what it calls for and charge with R-12 and you will be good. My 84 has all original parts with R-12 and it works as good as any system on any car. The secret to a good working A/C on the old 126s is cleaning the condenser and evaporator.

Paul

Hit Man X · #14 08-07-2011, 09:19 AM

Correct, it has to be a Diesel. '85+ will be fine, the '90-91 are what to prefer due to the dual aux fan bracketry... but of course the '90/1 350SD/L are just about impossible to find and the '85 MY had the larger fans.

The updated condenser really helps dissipate faster, if the system is dead or apart for repairs... do yourself a favor and seek one out. If not, just buy a new parallel flow.