From the looks of it I have the original condenser and a Delphi R4 compressor. The PO converted to R134a. The system has a leak on the compressor manifold and I have a replacement manifold I am getting ready to install.

What is the refrigerant capacity of the system? Should I charge by weight or pressures?

... in Florida? wow.

I'd start by removing the condenser, and making sure all the fins are totally straight, and chemically clean it extremely well... reverse flush it while you have it out.any black debris, and you need a compressor...

the R4 in the 123 is nearly useless above 88F... I'd say around 1.6 lbs R134...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thank you for the information. I'm going to give it a shot and see how it does. Even though it's Florida the temperature in the summer when I drive my commute is in the high 80's so it might be acceptable.

Is the best performance to go back to R12 or a Santech Compressor and Parallel Condenser?

R12 with original style compressor/condenser. R134 with Sanden and p flow condenser.

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Jim

R12 just as it was designed by MB.

94F here currently. 85 300D R4 134A getting vent temps of 58 F. Is that useless? Feels nice and cool to me. This is with no viscous fan, just the aux fan.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

In 85, MB changed the condenser design to a more efficient design. You are luckier than the OP... His 83 will have the old large tube coil.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

My 83 300 D never had working AC. But I did compare it to the 85 when I had both side by side, and the condensers were identical, same number of tubes same size tubes.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

An R4 in 94 temps can't be that bad, or at least better than the York on my 77 240D auto running R134a. We're seeing 98 this week.

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Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.

Anyone want to put down some wagers? I should be getting the dryer tomorrow and have it installed Friday.

R134a in the old style with the york IS WORTHLESS. Any minor cooling effect will be canceled by the tremendous drag from the compressor.

R12 with the old style york does work quite well. I can do 40* vents in my '78 no sweat.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

No wagers but just a WAG:

If the AC components are brand new up to spec, 40F at the vents 88 F ambient with R12. 45F with 134A

Since your car is over 30 years old, my WAG is: 55F at the vents 88 F ambient with R12. 60F with 134A

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

My 2 cents worth -

Back in 2006, my first diesel was a tired, rusty, '82 automatic 240D. It had a rebuilt R4 compressor of unknown age & condition, except it turned freely. But the condenser was broken open and had been that way for who knows how long. The car wasn't worth spending alot to fix the AC. So I installed a used replacement condenser and a new filter-drier, and one of those R134 conversion kits from WalMart. If I kept it parked in the shade, the AC actually worked OK. Parked in the sun, it took forever to cool down to barely tolerable.
Still, it was better than no AC. Cranking up the idle speed and shifting into N at stop-lights helped the AC cool better in traffic. Glad I didn't waste any precious R12 on this as it turned out to have a slow leak that needed to be topped-off after about 2 months! I charged it up and the AC was still working when I sold the car 8 years later.

I recently installed a rebuilt R4, new filter-drier and expansion-valve on a friends beater '84 300D. The car had the R134 conversion so that's what I used. The new expansion valve was identical to the original, but was marked 'R134'. So far this converted AC has performed better than the conversion in my first 240D.

In the past 9 years I've had a couple W123s with working R12 systems. Those definitely outperformed the R134 conversions.

Happy Motoring, Mark

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DrDKW

One more question. Which oil should I use? Some quick Google says PAG 150.