I've got some really dumb AC questions for a patient person (w115)
 

Hi Folks,

The york compressor in my 220D (worked fine last summer) leaked out all its lubricant/refrigerant.

I removed it and have a new sanden/bracket ready to install, as well as a new receiver dryer.

Do I need to have new hoses made or purchase any fittings? or do the old hoses connect to the new sanden unit?

Are there any other parts I should replace? Not looking to break the bank- thinking I'll flush the system and put in some R 134.

Replace your expansion valve/orings if you can.

I believe the original/oem system works best and York compressors can be rebuilt.

https://www.youtube.com/watch?v=6Qmsm12oo18

No

I tried R-134 in a W123 and found it to be quite unsatisfactory. Went back to R-12 with far better results.

Success with 134a depends on the condenser and aux-fan arrangement. More condenser and more airflow is required to get good performance. If you have the original coil and fan setup, stick with R12 or use one of the hotly-debated alternatives.

I have a Mercedes condenser (built in 2014), original fan, orings replaced all over, suction line/crush washers replaced, new expansion valve, new drier (BEHR) and a Spectra Premium A/C Compressor off of r ockauto

System was tested for leaks, vacuumed for over an hour, filled with R134a (2.6lbs) and works perfect on the hottest days. It may take 45 seconds-1 minutes longer to get to ambient cooling temperature but I assure you, it's the same temp coming out of the vents at idle after a minute then R12.

Let's measure and go on the data however - If someone here can measure their vent temps with an true R12 system, I will compare my results and I assure you, they are the same. I have a 1985 300D W123. Stay away from R12 it's terrible for the environment.

From my own experience I say don’t even waste your time with r134 in York compressor.

Also, york compressors have an oil sump. So, you probably lost some oil with your refrigerant leak but not nearly all.

I would concur as well. The oil in your York was compatible with R12 (most likely mineral), so if the system is charged with R134a, the added oil (if it is not the same as what was in there originally) will cause problems. When changing refrigerants, it is best to completely flush the evaporator, condenser, and hoses. Also, the hoses on your 35+ year old system were made for R12. R134a has smaller molecules than R12, so it will leak out of the already leaking old hoses a lot easier. As a rule, when refrigerant leaks, oil leaks with it. If you want satisfactory results from your revived York system or Sanden retrofit, all new hoses and a complete system flush is the only way to expect your A/C to last more than a season. As said, you can use R134a, but an upgraded condenser (parallel flow) and larger fan is a must. A York to Sanden retrofit is in my opinion better than a rebuilt York. Many of the rebuilt compressors nowadays are built using Chinese parts, and don't last very long. Best to go with a new Sanden, or an NOS unit with the green sticker (made in Japan or Singapore).
IMPORTANT: Any new compressor will most likely be filled with PAG oil for use with R134a. If you are using R134a, no problem. If R12, the compressor must be drained of all the oil and proper oil installed. I like Ester oil for R12, or R134a, but most use PAG for R134a. If you get an older or NOS Sanden, it is best to drain it anyway, and start from scratch with the proper oil.

How hard is it to convert a system back to R12?

When it's over 90° here, my new R134 system struggles unless I'm barreling down the highway for 30+ minutes.

You have other problems then. Likely the recirculation flap isn't working and/or your charge is incorrect. R134a is less efficient than R12, but it isn't THAT much less efficient. It's been in the mid 90s and extremely high humidity for this area lately from all the rain, even with that, after sitting in the sun all day and getting heat-soaked, it only takes my SD about 5 minutes to pull the cabin down and start blowing ice cubes on R134a on the stock system.


Charging a converted system is an art, not a science. If you just dump in a weighed amount that some Internet armchair "expert" claimed was right, you'll be wrong, guaranteed. You'll be under or overcharged, neither of which lend themselves to good cooling.

Everything needs to be flushed (not the compressor though), and new oil installed (mineral or Ester for R12). The compressor needs to be drained well. Of course the fittings need to be for R12, and the drier replaced.

Sandens come with many different rear heads. Check ebay. You can swap heads for $20. There is also a universal head which has adapters. I recall one is for the uncommon Ford ports (Roto-lock or such) which were on their Yorks. I don't know what ports M-B Yorks had. But, your hoses probably have old rubber, so why not make new hoses and put a fitting at the Sanden ends to match the standard today which is #6 O-ring for outlet and #8 O-ring for suction. Recover your M-B fittings to use on the other side (hacksaw the ferrule and bend off). A shop can crimp new ferrules or you can buy Oeticker stepless ear clamps on ebay. I suggest "reduced barrier" AC hose. You can get Sanden heads with those ports on the top (most common) or end.

BTW, are you using the common "York to Sanden" adapter bracket? It would bolt to your existing York bracket and has curved slots to tension the Sanden belt. I have one I was going to use on one of my Mopars, but changed my mind. I thought it was aluminum in the ebay ad, but someone just painted it silver so is still a bit heavy. Anyway, PM if you want it cheap.

I use HC refrigerant (Duracool) in all my 7 vehicles. PAO 68 oil (Hella) is best for any refrigerant and compatible with all. But, first read all the fears from people who know nothing about combustion all over the internet about HC being "explosive".

Well said, with one exception: The Sanden rear and vertical port heads use a #8 & #10, not #6 & #8. I would also add that the older Sanden compressors with the green sticker (made in Japan or Singapore) are much better than the latest version (made in USA- most likely with some Chinese parts). Like Bill said, ebay is a good source for the NOS compressors. Changing the head is a small price to pay for a good compressor. If no luck on ebay, A/C Parts Warehouse has the best price for the new Sandens.

thanks for all the input guys!

just to update - I replaced the york with a rebuilt york unit. I decided to get the AC in the 220D going as cost efficiently as possible since I would rather upgrade my much nicer W123 to a sanden and replace all the AC components along with it so it's all done correctly. I care much more about that vehicle lol :D

Just about have everything together and hit a snag though:mad:

the tensioning pulley that bolts to the massive york AC bracket has stripped its threads! Weird thing was I wasn't even tightening it that hard...

I'll try and use a threaded insert on that today and let you all know how its working.

I may have not received the situation well, but you're right. Turns out I have a show leak.