1983 300D Turbo, previous owner says it was converted two years ago to R134A, but I can't find any documentation. I want to check freon level and add if necessary, but don't want to mix R134A if it has R12 in the system. How do I find out what is in it? Also, I noticed from other threads that when converting to R134A, the condenser should be replaced too...where is it and how do I know if it was replaced?
Thanks in advance!

The fitting for the R134 is a quick connect with threads on the inside of the fitting. The old R12 fitting looks like an air valve fitting. This is my R134 fitting............http://i63.photobucket.com/albums/h145/hotwheelbill/ac002.jpg
The old R12 , or stock condenser is a tube in fin type like mine.......http://i63.photobucket.com/albums/h145/hotwheelbill/ac001.jpg
It will work with R134 but as I have learned today, not very well.

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1985 300D burning WVO using 26 FPHE, half gallon heated fuel filter,glow plug heater,home made injection line heaters. Home made cold air induction. ALDA full out.
2003 F350 7.3(the last of the great motors)
1987 Paint Horse-non running too, just walks!

Are there any drawbacks to using R12's legal replacement, Freeze 12? If not, why don't I see the stuff in Auto parts stores?

On these things the best stuff to use is the R-12. I have tried r-134 and it doesnt work that well. The damned condensor is too small. If you get certified you can get r-12 at an auto parts store. I think it cost me $60 last summer.
I have used envirosave refigerant in my explorer and it worked great. Already 90 deg here so we need it.

Last time I checked there were approximately 12 alternative refridgerants to R12 that were approved by the EPA. R-134a and Freeze 12 are two of them. However, the only refridgerants that have been approved by compressor manufacturers is R12 and R-134a. I suspect the reason most auto parts stores only sell the R-134a has to do with the warranty implications of their own A/C components they cell and becuase the huge number of cars that come from the factory fitted with R-134a.

TimK

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EPA 609 & 608 HVAC Certified
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83' 300D Turbo - 300K + Miles
00' 1.9L TDI Beetle
85' 6.5L Turbo, GV-OD, GMC Suburban,
67' 2.5L Diesel NA - Land Rover Series IIA

Here's what you do if it's so cold your diesel fuel gels. Smear some on some toast and stay inside until it warms up outside.

I believe all cars manufactured since 1994 have R-134.


David
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1985 300D Turbo

I appreciate the comments, all are great. The problem is this: the previous owner says it was converted two years ago to R134A. I cannot find documentation in the records, and need to service the A/C with freon. I don't want to mix freons. I need to know if there is a particular way, other than the fitting appearance, what freon is in it now.

If I had the choice, I would not convert. But I want to know what state it is in now. Any ideas on identifying what freon may be in it now???

A properly done conversion should have included a label affixed that states clearly R134A and the date it was performed as well as special threaded shrader valves with blue caps.
Besides that the contents can only be verified by a test using the available testers, when an AC service shop does any work they have to (by law) recover the gas into appropriate tanks with different threaded hoses for each system.
Here's the racket in Calif anyhow but it may not be the same elsewhere:
The firms that buys recovered gas will always check it with a tester before accepting it and if the R134A tank for example has any traces of a hydrocarbon (flammable) gas or other than 134A they won't buy it back. The shop is stuck with paying to have it removed, instead of receiving a payment or being allowed to reuse it.
Without any records and if it doesn't clearly have the sticker and the blue caps on the fittings then you need to have it tested at an AC shop, I doubt they would do it for free but it shouldn't be very much. Otherwise you are at risk of messing up the system in a big way. And no telling what kind of oil is in it!

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!