I would second everything leathermang (Greg) has said regarding the proper way to do your A/C. I am currently in the middle of redoing the entire system on my 240D.

I would strongly recommend to going to http://www.ackits.com. They have a forum there which explains how to properly flush your system and A/C compressor. They are located in Phoenix. BTW, I even called them this morning to ask questions regarding vacuum pumps to make sure I purchase the correct one. My old one just went out on me this weekend. Be sure to buy a flush gun when flushing your system and buy lots and lots of flushing agent. Don't use the prefilled compressed air cans because you will go broke by the time you buy enough to really flush the system well.

The main thing to remember when doing your A/C is to do it RIGHT the first time. Take no shortcuts and be well informed before you start. You will have a great working system if you do all of that. It sounds like you are well on your way.

Feel free to PM me if you have any specific questions.

Scott

__________________
Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

[quote=JimmyL;1802093]In Texas during the dog days of summer even R12 doesn't cut it in these W123's. When you get in the car even with a windshield shade it's 130-140 degrees and unless you start out on the highway moving it takes a while to cool. And it still doesn't cool like the newer cars do.
R134A is just awful and above 90 it is just ineffective. You are lucky to get vent temps below 58-60 and when you are starting at 130.......
Further into the summer I will be getting the R134a outta China and probably try some Envirosafe just to see what it's like.
But, this thread ain't about me......

Jimmy,
One of the reasons I'm keeping my 123 is the AC is the best of any car I've driven or ridden in in Texas. On the hottest day, my R-12 system will make you feel "too cold" in a short time. I love it!

White 300D, blue interior, tinted windows, sets outside most of the time. Rebuilt the R-12 compressor twice and never considered any other coolant. When I need to fix the compressor, I remove it and take it to a compressor rebuilding shop in Denton. They reseal it and put the right amount and type of oil in the compressor. I install a new receiver/dryer, any new O rings etc. Evacuate to be sure the system is closed, add the right amount of R-12 (by weight) and run for another 5-10 years. Rarely have to add any.

Charles

PS: When R-12 was starting to be replaced, I had a mechanic friend purchase a drum for me (30 lb, I think - still more than half full). Best investment I've ever made!

I don't really expect there to be a serious shortage of R-12 in my lifetime, or my cars' lifetimes (hopefully longer than mine). The worst thing that will happen is that it will get a little more expensive.

I've decided I'm going to get the 14x22.5" ackits.com pf condenser and go to a local A/C shop (in business for nearly 50 years) to have them make fittings for it, and put it in.

I might also get a high CFM aux. fan, and wire it to the compressor switch so it's on when the A/C is on if I have money left over. And/or window tinting as well.

I think those upgrades, and a thorough flush, and converting back to r12 will be a good investment of my time and money for this summer. Saint louis becomes 100 degrees and 100 percent humidity quickly. I'll buy a flush gun, and a gallon of A/C flush solvent, drier, expansion valve, a good quality mineral oil, find the right o-rings, nylog for the orings. I already have 3.2 pounds of r12 so that's more than enough. I can score cans of r12 on eBay for low prices in seasons other than summer.

I'm going to use the compressor that's on it now, it's a factory air one that was new in 2000. R&R'ing would to be too much for me to handle. Maybe a filter downstream from the compressor wouldn't be a bad idea. Hopefully I won't find out that it's a stepped port one when I take off the hoses going to it.

I think I'll re-use flush by flushing once then collecting the used flush, re-using it a few times, then flushing with clean fluid, it should be more effective than just wasting the $25/gallon flush.

I will need some advice as to which o-rings to use, maybe the ackits.com guys can help out. Can the green o-rings be used in both r-12 and r-134a? Or are red orings for r-12 and green for r-134a?

Thanks once again for everyone's input, and as for refrigerants other than r12 and r134a, if this was my 2nd or third car and it had a converted r-134a system, then I would consider trying the alternatives. But with my only car I don't want a refrigerant gineua pig, and I'm lazy and don't like to re-fix things. Especially working on my car, when I botch things I turn to the zip ties and duct tape for quick fixes just to be done.

__________________
1980 240d
1999 SL500

It WOULD be easier to just do the conversion to the PFlow condensor... but that makes it sound like that will automatically make up for the molecular shortcomings of the 134a compared to the R12 in terms of efficiency. It may part of the time ...but the below quote from your thread spells out the situation also in real life (emphasis on TIP TOP ).... if your old Delco does the black death within a year due to the higher operating pressures AND you have not installed an iinline filter before the new PFlow condensor then you may have to buy a new condensor when the compressor goes... because the PFlow may not be flushable in the same way a regular condensor is....

"These systems will perform converted however due to higher than r12 head pressures, need to have a compressor that is tip top, Aux fans in order and the red fan switch in the dryer. We look for head pressures of 270/45 high blower, recirc at idle. To give you an idea of how sensitive r134 is the air flow, watch your lo side pressure rise about 10 punds per step increase in blower speed."--Joe P

"I would second everything leathermang (Greg) has said regarding the proper way to do your A/C." ---Scott98

Thank you Scott.

As to the amount of flush.... the AC manual for our cars shows what the factory suggests the dealers use.... it is a machine which has filters and recycles and cleans the flush as you are using it... so they can flush until they see a certain clarity coming out of the particular item being cleaned... So doing it at home needs to have plenty of flush available to use just like Scott98 mentioned.

No, the worst that will happen is it will get incredibly expensive fast because it has been discontinued since 1995. Some states do not allow the use of R12 in mobile systems anymore but the EPA has decided to let the market decide and this includes Alternative refrigerants including Envirosafe. Cars and other vehicles made before 1994 will require a retrofit with new seals and fittings just like R134A.

Oh, and I decided to include a couple of links backing up my claims. The first is an interesting one about the vehicle occupants who DIED because of a leak in the evaporator causing them to breath R134A! It turns out that R134A will corrode Aluminum, like the type used in Evaporators in our Benz's and too many have died this way in Europe and Japan!

http://www.autofrost.com/134aproblems/index.html
http://www.aa1car.com/library/tr497.htm

This link uncovers the truth about R134A and it's corrosive effects on the aluminum used in mobile systems!
http://au.geocities.com/OZBRICK850/interior-r134.html

This link exposes the realities of R134A in Europe and why R134A is not recommended for mobile use. I find it interesting that they find hydrocarbons more easily tolerable than R134A and since Europe including Germany isn't under undue influence from DuPont like we are in America!
http://www.aurora-eos.com/en/dmh5j.html#3

Europe has already discontinued use of R134A in mobile systems because of the hazards and has widely accepted Hydrocarbons like Duracool and Envirosafe. http://www.idealcoolantsolutions.com/index.htm
Distributorships for Oregon and Washington? Legally? Hmmm.

This article in the Idaho Observer talks about the real benefits of Hydrocarbon based refrigerants without the hype. "It turns out that the ability of HFC-134A or R134a's to damage the environment is just the beginning of the inadequacy of HFC-134A to be a replacement for Freon!" The part of the rest of the world embracing the use of HC 12, like envirosafe and Duracool are "seriously disturbed by the rhetoric of the proponents of HFC's, like DuPont and this is causing the United States to seriously lagg behind the rest of the world where the benefits of Hc 12 refrigerants greatly outweigh the risks!" Really? I never would have gessed! I guess this is why Coca Cola, Matsu****a, Bosch, Unilever, Sanyo, Siemens, DeLonghi, Electrolux and Hitachi, to name a few have begun to make HC refrigerant based appliances in 2002. The US is the only one who doesn't! Really? I wonder why that is!

Oh, R134A is toxic and deadly at concentrations of only 4 parts per million!
http://www.proliberty.com/observer/20020406.htm

Environsafe is illegal here in Texas...

http://www.epa.gov/Ozone/snap/refrigerants/hc12alng.html#q15

It's always made me laugh how Mercedes made bad a/c units ... FOR YEARS. They would never admit they made (or bought and installed and sold to us) CRAP! And when they were nothing but problems, what did they do? Continue to make them and sell them to us!

I called MB a few times to see how I could get an a/c from a 1989 Toyota Tercel into my MB so I would have air conditioning. Just anything to shame them enough, as apparently nothing else would work with them, to where their brains would start working, and they'd get a good a/c unit in.

That all aside, I heard there's something new (at least new to me), that is supposed to be super cold, and it works in the standard a/c's, not the new converted R134. Call around, the people who used it said it really works. Maybe even check ebay to see what's up there.

Good luck with it.

jeff

In certain States, it's illegal for a SHOP to charge your system with HC's, but the EPA has decided to let the market decide for the self servicer. Under the laws of SNAP, you could also LEGALLY retrofit your AC system to use R22!

Hell, if it works, I might try it!

Not True.

http://www.epa.gov/Ozone/snap/refrigerants/hc12alng.html#q15

Is it legal to replace HFC-134a in a motor vehicle with hydrocarbon refrigerants such as DURACOOL 12a® and HC-12a®?

"....
The following 19 states ban the use of flammable refrigerants such as HC-12a® and DURACOOL 12a® in motor vehicle air conditioning, regardless of the original refrigerant: Arkansas, Arizona, Connecticut, Florida, Idaho, Indiana, Iowa, Kansas, Louisiana, Maryland, Nebraska, North Dakota, Oklahoma, Texas, Utah, Virginia, Wisconsin, Washington, and the District of Columbia.

EPA and hotline staff will not, based solely on facts given in a phone call or letter, determine the legality under the SNAP program of using a hydrocarbon refrigerant in a motor vehicle retrofitted to use HFC-134a, because the determination depends on many factors, including the nature of the retrofit from CFC-12 to HFC-134a, the reason for the retrofit, and the exact procedure and timing involved.

If you plan to change a car from HFC-134a to a hydrocarbon refrigerant such as HC-12a® and DURACOOL 12a®, you should consider that auto manufacturers have stated that changing the refrigerant in new vehicles designed for use with HFC-134a will void the warranty and may damage the system. If the air conditioner on a new car or truck is not working, consult a qualified mechanic or your dealer. "

http://www.epa.gov/Ozone/snap/refrigerants/lists/chiller.html

"Unacceptable Substitutes (2) Name (1) Date Manufacturer Reason
OZ-12® 3/18/94 OZ Technology Flammable blend of hydrocarbons; insufficient data to demonstrate safety
R-176 3/18/94 Arctic Chill Contains CFC-12, which is inappropriate in a CFC-12 substitute
HC-12a® 6/13/95 OZ Technology Flammable blend of hydrocarbons; insufficient data to demonstrate safety
Duracool 12a 6/13/95 Duracool Limited This blend is identical to HC-12a® in composition but is manufactured by a different company
R-405A 6/13/95 Greencool Contains a perfluorocarbon, which has extremely high global warming potential and lifetime"

If this stuff is so illegal, then why did I pay a hazmat tax in Arizona for it when it was shipped here?

It is not illegal in all states..... and it is not illegal in all applications....
There are about 15 states including Texas where it is illegal for mobile Air Conditioning systems...

It is stupid in all states though.... but doing stupid things is not always illegal....

I would really like to see that list of the states the doesn't allow the use of R-12 anymore, so far you've told some vague story about how it's "discouraged" in AZ. AFAIK, it is perfectly legal and readily available everywhere in the U.S. (it is certainly legal and available in CO, and there is plenty of it on eBay) You do get to have your own opinions, but you don't get to have your own facts. Either come up with a reference or stop telling people that it's illegal to use the correct refrigerant in their cars.

As for the cost of R-12, I guess it depends what you consider "incredibly expensive." I think I paid $60/pound last time I had some added, so it has a very LONG way to go before it's expensive.

Personally, I don't care about R-134a or any of the "alternative" junk. R-134a doesn't work well in our systems and there is no good reason to play with that other stuff. Just use the correct refrigerant and be done with it.

Even that is HUGE cost-wise... I paid $340 for 30lb tanks a few years ago.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

You know better than that, it is not illegal to buy in AZ; but it is illegal to use in automotive systems in many states (including AZ IIRC). You can do what you want, and you will probably never get caught; that doesn't make it legal (or smart).