Need R134 A/C conversion specs for W201
 

Can anyone give me the specs for the oil and the freon needed to recharge a 1986 W201 190E 2.3-16v A/C after conversion from R12 to R134?
Thanks

I'm getting ready to do that to mine.

I got this so far for info:

Capacity: 1000 g Refrigerant R 12, 2.2 lbs. That's about 3 cans. I think the amount of R134A is different.

10 to 12 fluid ounces of oil

Agreed
 

Thanks. I had the 2.2lbs number too. Just wasn't sure if it was an R12 or a R134 number. If it is the factory R12 number I can work with that. From what I can see the amount of R134 is less. Not positive how much less. Seems to be 10 to 25% less depending on who you ask. Any one have a definite number?
Thanks.

W201 is 2.2 lbs of R12.

Typically you put in 80% of that in R134, so 1.76 lb of R134a.

Just charged up my 201 last night. Leaky shrader valve forced me to do it. Used ES-12A.

Sounds great
 

Great. Thanks. I will go with 80%.

Leaky valve
 

I have had the old leaky Schrader valve trick myself. I have several cans of R134 in the garage so I will go with that. How is ES-12A different? Don't know about it.

ES-12A is an alternative refrigerant. It is a proprietary blend of propane, butane and some other chemicals.

Its supposed to be more efficient than R134A/R12. It supposed to have lower head pressures and be better for the compressor. It has a larger molecule as well so that might help too. Its pretty cheap too. 12 cans is only $60. My 201 took 2 cans and it runs nice and cold.

When I put it in my W124 (which was converted to R134A previously) it eliminated a noise that the a/c compressor would make, so I take that as a good thing.

Its cooling performance is pretty good compared to R134a. At 85-90F my 124's cabin is very comfortable, even with my broken center vent pod (no center vent air).

The only down side that I have encountered is that at low speeds and idle it does not cool as well but I think that is also true of R134A.

I know a lot of people on here that are against using alternative refrigerants and are for using R12 in an R12 system but I just don't have the time, energy or desire to deal with going that route.

I bought mine from here, along with a seal/valve kit.
Industrial R134a Replacement Refrigerant Details and Online Ordering at Enviro-Safe, Inc

HC-12a - Wikipedia, the free encyclopedia

A question about flushing
 

Should I? What would happen if I don't.

And how exactly do I do it, and what do I use for solvent?

Truth be told. I've never done it before on any of my cars.

I think flushing is more mandatory when you have component failure like a compressor and stuff gets thrown into the system.

The internet seems to be divided about it. I was just wondering about getting the old oil out. I'm assuming some if not all will come out when the R12 is sucked out.

I'll probably get scolded by more experienced a/c folks here but I've never really done anything with the oil. I know that whenever I'd assembled a/c system that we'd always put oil in various spots but I've never added any while evac/recharging.

Now if you are going from R12 to R134a I do believe you have to change the oil. My recollection is that R12 oil is not compatible with R134a oil.

Sorry I'm not much help. The ES-12A stuff that I've been using is compatible with both so I just vac down, charge up and go on my way. (which could be 100% wrong way to do it too, but I've no issues in the 3-4 years since I started using it)

Flushing
 

I was told to always flush a system that has had a compressor failure or when retrofitting to a different Freon. You can buy a can of flushing solvent with the hose attached in an aerosol type can at parts stores. Autozone and O'Rileys have it for sure. Not much flush needed to do hoses and parts. Just flush through so if comes out the other side and stop and let it evaporate. It works fast. Kind of like brake cleaner that evaporates.

If you have compressor failure the contamanation is likely through out the system and flushing is not going to remove all the debris. Eventually the replacement compressor will be compromised. I have four w201's all with working AC. Three on 134 and one on it's original R12. The smaller molecule size of the 134 will allow it to leak from a lot of places I think over time it slows and eventually stops at least that's what happened for two of my cars. I am here in the south so AC can be worked hard and the 134 is defiantly not up to the task in sitting and slow moving traffic. I am keen on the ES 12A, annectodatoly I hear it blows snowflakes sometimes.

I'm just the other side of Denver from you, lemme know if you need any W201 or AC assistance.:D
With a CLEAN condenser, and a working aux fan, and a lower temp switch, 134 should be fine in a 201 in nc.

This has been my experience as well in my 300D. It was R134A when I bought it, I ended up having to recharge it twice after it leaked out during the course of the winter/fall/spring.

No issues like that with ES12A, so far at least. Its only been a few months since I did the 124. The 201 was earlier this week due to a leaky valve.

About to start
 

But a question: do I pull and hold the vacuum before or after I add the oil?

After I would imagine. I dont think much of the oil comes out when you vac down. Could be wrong though..

The last 4 cars I've done I've vac'd down for an hour, let it sit for an hour, then charged up if everything held.

The one truck we did where we put an entire system in, we added oil then vac'd down for an hour, found a leak, fixed it, re-vac'd and then waited another hour. After that we charged it up with the appropriate quantity. Works pretty well.

I pulled a vacuum on it and shut the valves and pump off a couple of days ago, mostly to check for leaks, and it held. Would that count as running the vacuum pump for an hour?

How long was the vacuum pump running?

Long enough to pull a vacuum, about a minute.

If it were me I would not consider 1 minute adequate.

Ideally till it the vacuum is around 500 microns but I don't have that kind of equipment to read that, like the quote says below:

Denlors Auto Blog » Blog Archive Car AC Vacuum Pumps – FAQ’s | Denlors Auto Blog

But its not like you removed the vacuum from the system and charged into it directly... But if you closed off the valves and let it sit under vacuum for a while.. where does all the "boiled off" moisture go? It has to go somewhere.. If the vacuum pump was running it would have got sucked out and exhausted out the vacuum pump.

Any moisture would be as a vapor in a vacuum, even though it wouldn't go anywhere. Then in theory I could turn the vacuum pump back on and it would suck out the water vapor. I was thinking it takes time for the water to boil off to a vapor and as long as the vacuum stays low enough it should all be a vapor.

That was my theory, not that I checked it, I still ran the vacuum pump for a while. My real intent was to check for leaks and I don't have anything good to pressurize it with.

Pressure Testing AC
 

Are you guys doing any kind of pressure testing before Re-filling ?

Y'all know you can have a Leak(s) that cannot show up under Vacuum,
BUT is excruciatingly obvious when the system is pressurized with say Nitrogen.

When switching Refrigerants (Unless some genius had previously installed
lubricant that is safe to use with both "Before" and "After") The Compressor
is NEVER Flushed,BUT must be turned BY HAND until ALL the Old Lubricant is
removed.

No, I've never done any pressure testing. Never had access to nitrogen. It was always something that was going to be done "when I got around to it" these vac down and recharges were one of those "fix it temporarily and we'll deal with it how we originally wanted to later on"

Later still has not arrived. But yes the proper way is to check for leaks with pressure, like from dry nitrogen.

Sucess
 

So far anyway, I'll have to wait and see how long it lasts.

98 deg. outside, 46 deg. in the vent, nominal pressures. I'll do another pressure check is a little while.