was over at my indy's today and we got to talking about ways to get the a/c going again (R-12 system). he was saying he is using exclusively R-145a as a replacement for R-12 with no problems at all and no modifications necessary. anyone have any experience with this stuff? i am thinking about giving it a shot ( so to speak..)

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

Why are you not going to use R-12 for your R-12 system ?

This was all I could find on R145

http://www.ornl.gov/~webworks/cppr/y2001/pres/6127.pdf

That link sure was a "light" read........NOT. The obfuscating language in it is another example of government bureaucrats at work. How did you find that doozy?

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Call Don Freeman at Duracool USA regarding Duracool 12a. I was very impressed with its compatibility and marginally higher efficency than freon R12. It is 35% more efficient than R134a which I've read in the diesel forum does not cool well in the 300D. Only took 1- 6oz can of Duracool to bring my system up to cold. (''
Their Kit includes three 6 oz cans and each 6oz is equivalent to 15oz can of 134a and instructions to do it yourself!
Yes, I was skeptical however Don at Duracool owns a number of Mercedes Benz including the "83 300DT he purchased the day I talked with him. He is friendly, (that's diesel mercedes knowledgeable and friendly)('')and willing to give information and talk with you.
The tune up kit includes three cans of Duracool and a charge kit is $39.95 +7.50 SH/H.':
Check his Duracool site and call him monday! http://www.duracoolusa.com/
I am planning on using the extra cans to convert my 134a systems on my other vehicles to duracool 12a. The Chevy diesel van does not cool very well at all with 134a.

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'96 C220 138,000mi, '95 E300D 239,000 mi., '87 300TD 214,000mi '88 6.2 Turbo Diesel Chevy Conversion Van 253,000 mi.

" R-12 with no problems at all and no modifications necessary. "---84300DT

R-12 would not require any modifications ... and the system probably worked 20 years with it in the first place...

Why look for an alternative ?

only because the guy didn't have any r-12 and said r-145a worked. i trust him to give me the straight scoop but i wanted to check if anyone here had tried it. the system was working but i think it is low on freon.

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

Take it from an old guy... R-12 is the best stuff to use, the price is going down...not up anymore.... Your system was designed to use it...it was used by millions and millions of cars and all the parameters of the compressor were built to mesh with its properties....
The guy suggested R-145 because he had no R-12 in stock.. ? That is not a good reason.. maybe you should look around for a shop which does have it.. or get it off Ebay....
If your system has R-12 and it is just a little low... DON"T fix something that is NOT BROKEN.... check for leaks, top off the R-12 and worry about something else....

If you REALLY TRUSTED HIM you would not have asked that question here...... He is trying to sell you something... we are not... GO WITH YOUR INSTINCTS..... and do a search about 134a conversion to see the posts about sticking with R-12 if possible...

How about Freeze 12? If a system hasn't been retrofitted to R134a, is this a decent alternative?

Speedy, if it has NOT been converted to R134... PUT the R-12 back into it... don't be looking for " alternatives" when the RIGHT stuff is available for your car....There are NO NEW and IMPROVED refrigerants better than R12 for your car....That is an advertising concept we have been conditioned to look for... in this case it does not exist.... The newer cars have bigger capacities to compesate for the less efficient refrigerants they use... your car needs the R12 if you can manage to keep it....

yes greg i am fully in agreement that r-12 should go back into the system if possible, and i have been reading the posts, but i never saw a reference to r-145a, thus my enquiry. i don't want to convert to 134.
the indy wasn't suggesting i put anything into the car at all, only that his experience had been all good with the 145a in r-12 systems so that's why he used it.
the guy's a friend and so yes i do trust what he says and that he's not trying to 'sell' me something that's gonna mess up the a/c which isn't working anyhow. if i asked him to get r-12 he prolly would.

oh, and seeing you're 7 yrs older than me i guess yeah you're an old dude but i guess that makes me one too!

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

Howdy,

I'm certainly not an automotive A/C expert, but I drive alot of older cars, so I've done some research.

The ONLY legal substitutes for R-12 (or any ozone depleting refrigerant) are strictly limited to those listed on the EPA SNAP website:

EPA SNAP

Use other substitute refrigerants at your own risk. Once a system is converted to R134, or was originally an R134 system, it is a "grey area" as to what you can and can't use as a refrigerant. The EPA is charged only with regulating ozone depleting refrigerants.

Duracool is a hydrocarbon (flammable). I personally have no problems with this, but flammable refrigerants in any mobile form are strictly illegal in a multitude of states (including Oklahoma). Heck, we have cockfighting, but not flammable refrigerants.

To use Duracool, you MUST perform a PERMENANT conversion to an acceptable SNAP alternative first and then convert to Duracool. This means brazing in the correct fittings, charging the system, changing out the drier, etc. To then convert to Duracool would make the whole procedure $$$. If you convert directly to Duracool, your A/C guy can do jail time.

Another thing I noticed in the research I did is that both Duracool and R134 seem to have a critical temperature at 150 deg F. See the chart below:

pressure temp chart

Below a condenser temp of 80 deg F, Duracool has a lower vapor pressure than R12, which is good. Above that, however, Duracool is HARDER to liquify than R-12, but easier than R-134. Above 150 deg F, you CANNOT liquify Duracool or so it would seem. I'm sure that this is an oversimplification of Duracool's refrigeration properties, but on a hot day the evap could be running pretty hot.

Like I said, I'm no refrigeration specialist...

Sholin

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What else, '73 MB 280 SEL (Lt Blue)
Daily driver: '84 190D 2.2 5 spd.

The reason most people are looking at alternatives is they can be purchased without a license/certification and can be easily added to the a/c system with existing tools used with R12. Topping off the system with R12 is costly since many places will tell you they can't fill your system without accounting for and "fixing" the leak. That might be a seal or two and when you get the final bill you are probably looking at $150 or more. The cost of alternatives is significantly less than that. I agree the best thing to do is use whatever refrigerant the system was designed for.

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99 E300 133K
98 ML320 99K
87 Saab 900 Turbo Conv 123K

My indy converted my 300D to R134 2 years ago and it is plenty cold, no problemo.

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85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

All automotive systems that I know of lose a little refrigerant over time.
One reason may be that the front seal on the compressor was designed to be lubricated by the oil in the system, which is pushed to it by the refrigerant.

Even if I am doing every bit of the ac service on my vehicle the proper procedure to test the system is to fully charge it , start it up and check for leaks... if you find any you save the freon to a container , fix the leaks, and put it back into the system......

I believe it is the last procedure, the saving to put back in which causes so many people to go for alternatives which they can simply vent to the atmophere instead of worrying about keeping.

It may be 5-10 years or before a tight system needs any topping off...

But you don't want leaks at service time because ( as far as I know) they only get bigger over time.... and you don't want to lose any type refrigerant..

In any physical set of examples you can have all the range of possible results... some people get lucky with their combination, etc... but what I am saying is designed for maximum cooling with the lowest overall cost in the long haul for the most people. You have to figure in things like the cost of replacing compressors that fail due to higher strain, etc, etc.... to compare long range...

It is not my car we are talking about here,,, and it is not only the people who are posting in this thread who are reading this ... I don't care if I ' convince ' any of you to change what you want to do... but I think it is important to state for the record some of the possible drawbacks to those who may not have the time/experience in this field some of us do....

If you look at the ASE website, Freeze 12 is just a 134a blend!
If you are concerned about having to have a licsence to purchase R12, just go to the ASE website and take the test to become certified. Takes about 30 minutes to take this open book test, and a $15 charge.
Jeff

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1971 R600 Mack toterhome (SuperDawg)
99 NU-WA Snowbird 34+2 SE 102 5er
If it's not diesel, it's not in my stable!
53 F100 617.951/auto
95 Dodge 3500 Cummins/5 speed service truck