Is that what you installed on your 240D? If so, how did you change the lines and bracket to fit?

Amazingly, the factory AC still works in my '81 240D, though I believe the PO has replaced the original AC-Delco R4 compressor with a rebuilt at least once. Even with R12, here in VIrginia Beach it wasn't so good in yesterday's sunny high 90s, but it worked great after sunset, with high 80s and high humidity.
(And I can drive my Nissan Altima when I really need AC)

The York could certainly be more durable than an R4, but they tend to be rough and noisy, at least in the older Benzes that used them.
There is a bracket-kit availible to retrofit a Japanese Sanden compressor in place of the York in the older W114/W115 cars. So far, I haven't heard of a compressor upgrade for the R4 in the W123. A Sanden or Nippondenso would be my preference, but the lines and bracket would still be a problem.

Happy Motoring, Mark

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DrDKW

I beg to differ with rrgrassi. The aux fan is activated by either of 2 sources. One is by a freon pressure switch on the receiver-dryer and the other is by a water temp switch in the head of the engine.

The idea of wiring the aux fan to the compressor switch is interesting. I've never heard of this, but it should be fairly easy to do. However, it might be better to wire it for direct control of the driver - unless the driver is forgetful or insists on chatting on a cell-phone while driving.

I agree with the rest of you guys. R12 is the best option, especially if the car comes with it originally. I think that soon 134a will go the route of other goverment follies, such as ugly shock-bumpers and non-Euro headlights.

basically, you remove the push-button ccu panel, the face plate should just pop off, revealing a few screws beneath. Once you get that off, locate the vacuum valves above and behind the buttons, there are 5 of them. The idea is to tee the far right vacuum line into the line going to the valve immediately to the left, i.e. the one right beside it. I just used a bit of spare vacuum line and an old 3-way rubber Y. Here's the extended version.http://db.mercedes.cx/mb/199904/15/0010.html

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1985 300D Gretchen (Astral Silver) 220k
1983 240D 4-speed Evelyn (Orient Red) 203k


TANSTAAFL

[quote=Lux;1586521]Here's my take on r134, now that it's about 111 degrees outside right now. Wish I had been patient and waited for my mechanic to get me some r12.

I'm lucky if I get 62 degrees out of the vents the last few days.


-62 degrees at the vents when its 110+ is impressive. Not to mention, relatively extremely cold. I think most of us would be quite happy with a 50 degree temp. differential. And of course it is the relative temperature that you feel, to some who may spend all day in an overly chilled office say 69-70 degrees when its 95 outside, there may be little you can ever do to not be nicely chilled during your evening commute. Short of throwing lots of money at an a/c system that was an afterthought to the original designers.

__________________
1985 300D Gretchen (Astral Silver) 220k
1983 240D 4-speed Evelyn (Orient Red) 203k


TANSTAAFL

I have been viewing these posts about "returning A/C systems to R12 after converting to R134a" for some time and now feel I must respond. As an ASE Master Tech, MACS and ASE A/C certified, I have converted hundreds of vehicles to 134a including my 300SD and my 87 Ford Escort Diesel. I live in the Tucson, Arizona so A/C is of paramount importance to me! I use it 12 months out of the year! Do I believe R12 is causing global warming ...NO. But that's another subject. The price and availability of 134a, make it the choice of professionals especially with the counterfit R12 that is constantly showing up. With this said I would like to give some pointers:

1. Most conversions do not cool as well due to improper charging.
The proper charge of any A/C system is when the inlet tube to the evaporator and the outlet tube from the evaporator are equal in temperature with the engine at 1200 to 1500 RPM and the blower on High! This indicates a proper charge. If the inlet tube is cooler than the outlet the system is undercharged, if the outlet tube is cooler than the system is overcharged. These tubes need to be checked between the evaporator and the "H" block (Expansion valve). This is best done with a full contact digital thermometer, not the infared types although they will give you a good idea of the temps.

2. Air flow through the condenser is important
R134a does require the condenser to be efficient! It is not as forgiving as R12 if the condenser is partially blocked with bugs, and road trash. Here in the desert it is not uncommon to find condensers partially blocked with dust. I am refering to the back of the condenser, the side that is close to the radiator. Clean it by moving the radiator back toward the engine and clean the condenser with simple green or similar product and spray back through it with water. Do Not bend the fins with high water pressure as that will cause poor cooling as well. If the fins are flattened in the front of the condenser, straighten them. A little time with a small screwdriver and some patience will straighten them out or $5.00 at your local parts house will get you a "Fin Comb" that will do the job quicker.

3. Keep outside air outside
All outside entry points of air into the passenger compartment should be checked for proper sealing, as hot engine air will quickly offset your A/C's cooling ability.

4. Heater valves leak!
Be sure the heater is completely turning off. Most heater valves will fail to completely turn off the water flow long before failing completely. Both heater hoses, inlet and outlet sshould be checked. It the outlet is hot, you have a internally leaking valve.

5. Good airflow through the evaporator is important and many older cars have failed gaskets around the evaporator plus some clogging of the fins which forces the air around the evaporator rather than through it.

I am sure there are other things that others will point out about this post, but this is just my 2-cents worth after being a professional wrench for 36+ years. HTH

__________________
Retired
ASE Master Car / Light Truck
ASE Master Medium Heavy Truck
EVT Master Technician Ambulance
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"Without Fleet The Pride Doesn't Ride"

1983 300SD 609K + still going strong!
1970 Monte Carlo
1994 Ford F150

I'm glad that R-134a worked for you, but I'm done using anything except R-12 in these cars.

AC IN CAR NUMBER THREE...
R-12 is the only way to go. In an earlier post in this thread I asked about why the AC in my newly acquired 85 300D died after three days...had new compressor, lines, etc. No charge in the system = no low press = no comp clutch. Did the dye thing and found yellow on the little manifold to compressor...poor seating when the new stuff was assembled.

New gasket, proper alignment, torque, vac, charge = 47 degress standing still, 40 degrees moving -- both in 95 degree ambient.

Yes, I'm going to retro my retro and get R-12 back into car #2!

AC IN CAR NUMBER TWO.
Speaking of car #2, here's a stumper (for me anyway): I did a coolant flush on #2 today. During the various steps of the process one is required to run the heater on high. Flicked the whizwheel to the red stop and indeed eventually got hot air...BUT...when checking around under the hood, I noticed the AC clutch engaged! What's with that? CC Unit?

Thanks in advance.

__________________
FRANKNBENZ

1985 300D "Old Blue" 265,000 (parts car )
1985 300D "Gray Ghost" 245,000
1985 300D "Silver Bullet" 160,000
1975 914 VW/Porsche "BC Car" 125,000
2010 Prius "Shocking!" 60,000
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Thanks for the info. Im going to check into it. Tom

About six years ago, Helmut (or was it Hermann?) told me that the evaporator was bad on my 90 2.5 Turbo, and that he could replace it with a more efficient and less trouble prone copper evaporator for $1200 or so. When he got into it, he called me and told me that he had said Copper evaporator in the shop, but alas! it would not fit and all he could do was to install the original-type aluminum evaporator. And, by the way, my blower was also not working and ALSO need to be replaced.

After laying out around $2300, the system stayed cool for about two years. Now all the R134 (I unwisely had it converted) is wafting perhaps somewhere above Antarctica, and the blower has ceased to blow.

I have not managed to find even one sentence about a copper evaporator online, either. I suspect Hermann (or was it Heinz?) was and may very well still be full of crap.

Further work done by these two eventually cost me upwards of $5000 on a Diesel pump, a turbo, a fuel pump and even a new computer. All this was allegedly caused by water (and other contaminants not added by me) in the fuel.

I no longer take my car to either Hermann or Helmut. They have had a falling out and each has his own shop and neither speaks to the other.

Both of these guys MAY be actual mechanics, but I have never seen either dressed for such work, which seems to be done by Central Americans. Mostly, they took turns schmoozing with customers.



Does anyone know anything about a copper evaporator

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Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)

Hi HTH,

While it is true that R134A conversions can work better than most of them do and your points on what to look for are very valid, it is impossible for R134A to be as efficient as R-12 without violating several Laws of Physics. The thermal properties and temperature pressure curves simply won't allow it.

There are a few refrigerants that both theoretically and in actual practice will equal or exceed the efficiency and capacity of R-12 but R134A certainly is not one of them.

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Ron Schroeder
'85 300 Turbo Diesel 2 tank WVO
'83 300 Turbo Diesel 2 tank WVO
Some former WVO vehicles since ~1980:
'83 Mercedes 240D
'80 Audi 4000D
'83 ISUZU Pup
'70 SAAB 99 with Kubota diesel
'76 Honda Civic with Kubota diesel
'86 Golf
Several diesel generators
All with 2 tank WVO conversion
LI NY

[quote=ichbineinekrous;1593903]I get 57-63F temp from the vents on the freeway when it's over 100F outside. In stop and go traffic I get somewhere around 74F. Impressive as that may seem to you, my sweat-drenched body thinks otherwise! The temp inside the cabin--which starts at 120F from the parking lot--falls very slowly even with that kind of temp differential. It also causes the engine to overheat.

Of course, the money the shops are asking for a new R-12 system would be enough to buy me a decent used car that had a REAL A/C. I guess I'll just have to bear this summer heat and wait for fall.

I would go with Envirosafe if you need to convert your system. If it is already converted to R 134, leave it and see if it works for you! I live here in the valley and I've converted over to ES-12. Only because i had to change a compressor anyway.

the block hasnt changed through out the years, so the old brackets from the 115's will fit the newer 616 engines, 617 engines im not sure. One thing about the freon to use, i suggest freon R420-a its much cheaper than r-12 yet it has the same pressures and doesnt fractionate even though its a blend so you can top it off. it costs about 130$ for a 30 pound can of the stuff, ive had it in my 1981 240d with the R4 compressor for a year or so. it worked great until the compressor froze for no reason at all, gota love those american compressors, wich is why im converting over to a york pistion compressor, after i do my engine swap to a 617, mating it with my 4spd tranny. Oh and about the brackets, ill be either taking the old ones off of a w115 and transplanting it onto my mercedes, or custom fabbing the bracket myself. the only reason i can do that is because i work at a diesel engine shop.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.