What are options to get the most/best/easiest to maintain cabin cooling in a W123?

Looking for a long term solution for a Florida car, open to all ideas, but I'd rather not be attaching an auxiliary condenser outside the grill

Rollguys Sanden compressor mounting kit and Sanden compressor and electric fan control and updated parallel flow condenser will do the trick.

The p flow condenser will allow you to run r134 refrigerant.

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Jim

If it is an R4 compressor I'd replace it for your use case. R4's never impressed me. The York and the A6 were good but used up a lot of power.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

This is the answer.

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1981 240D 4sp manual. Ivory White.

I had a Sanden compressor on my 1985 300D until the Rollguy bracket cracked apart (first design), so went back to an R4. Didn't notice any difference with the Sanden. It doesn't cool well unless moving. The little condenser fan is insufficient when idling at a red light, at least for inland California (116 F record). But my 2002 Chrysler minivan is the same. The AC blows noticeably cooler once going >30 mph. I use Duracool refrigerant, which is slightly better than R-12, with PAO 68 oil. Have the factory condenser.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I agree with Bill. My 84 wagon has a sanden compressor and parallel flow condenser while my 82 sedan has a completely factory setup. They are both running envirosafe at the same pressures. They both cool the same which is very well on the highway with performance dropping off in stop and go traffic.
The condenser fan is wired to run continuously on the 84, but on the 82 it cuts on consistently as soon as I slow down in traffic so even that mod doesn't seem to do much when the weather is hot and humid.
I honestly think the evaporator is simply too small to perform in traffic when the temps get in the mid to upper 90s.

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1985 300 TD 448K
1984 300 TD 278K

1983 240D euro 240k
1994 f-250 idi turbo 330K
1986 f-350 IDI
1987 F-350 IDI

1985 JD 1050 4wd
1965 IH 3660

These (condenser/compressor) aren’t easy though.

Shern - I know you did the Sanden, Parallel flow condenser and alternative refrigerant to get an ice cold system. What percentage of the gain would you have achieved if you just did the refrigerant alone?

My feeling after doing my 300d with R134a + parallel flow + R4 was that the parallel flow condenser made a huge difference but I was using it as a crutch because R134a refrigerant just didn’t work well. It was like the condenser was a patch on inappropriate refrigerant.

I’m wondering if easy would be just putting in R12 cans bought on Craigslist. Or one of the new alternative refrigerants like you used.

Funny thing I’m currently cleaning out my parent’s garage up in Altadena. I’m finally selling the home. I found my dad’s stash of R12 from the 1980s. All the cans were un pierced but they are empty. I guess they had slow leaks and the Freon all leaked out over forty years. I thought I’d found a gold mine till I picked up the empty cans.

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles

It's a fair question.

And the truth is that prior to upgrading, I wasn't paying nearly enough attention as I wasn't financially invested. It was only after the upgrade that I bought a thermometer and started chasing after incremental gains. I'm sure there's a name for this sort of cognitive bias.

The other thing is, I started using AC a hell of a lot more after installing the sanden, probably to get my money's worth.

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1981 240D 4sp manual. Ivory White.

The Klima parallel flow condenser made mine noticeably colder. Is your aux fan working?

All the suggestions here will work however, I clearly remember the 240D my buddy bought that had everything factory and blew ICE COLD AIR IN YOUR FACE to the extent that he complained it was too cold .

My point is that when I was a young Mechanic I worked with a few Techs who'd slowly charge the system and stop when they got 40* F out the dashboard vents .

My Factory & Dealer training the instructors all railed against this but it does seem to work and not stress the system out by too much Freon .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

This is "better safe than sorry" and only risks suboptimal performance rather than the compressor damage risked by overcharging.

Charging a receiver/TXV system this way you are basically charging to a full liquid column which is "good enough" until you lose a little charge and performance falls off rapidly. But you can always top it off again.

I'd still always recommend charging properly with gauges and temperature probe if you can.

On the original topic, don't convert to R134a. It's a poor substitute for R12 and requires swapping out the oil. All that work for worse performance. Just use Duracool R12a or similar.

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1993 300D 2.5L Turbo

Sounds good to me, what do you recommend got high and low pressures and at what engine speed ? .

I'll go buy some Duracool R12, see what it's made of .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

AC systems can work just fine several oz under max filling...
but ONE oz over and it will work the system to death and not cool like it should. The whole principal is the difference in refrigerant between the sides.
I only fill by using a pro scale now.
Using temperature has some variables which can mislead. The temperature of the air out of the center vent is checked with AC on HIGH
BUT THE FAN ON LOW.... so the air is in contact with the evaporator fins the longest possible.....and the windows of the car are to be open AND you really need a GREAT fan blowing into the Condensor.

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html