The car is 91 420SEL.

Also, another stupid question. What would happen if R134 was added to the R12 AC system?

THanks

__________________
1991 420SEL Project Car (Completed and rides beautifully) http://www.peachparts.com/shopforum/tech-help/112321-free-1991-420sel.html
2000 BMW 740IL
2000 Integra Type R - Track Car - SOLD
2005 S2000 - Track Car
06 C230 Sport
89 560SL

bad things if they are mixed....due to lubricant issues acids can form and eat out the system from inside-out.

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

Here is the thing.

Stupid me!. I inherited this car. The engine was removed for overhaul and reinstalled. The AC system was completely discharged. Without thinking and knowing whether the AC system is R12 or R134. Stupid me went ahead and recharged the AC system with R134 2 days ago and the AC has been working great.

Let assume the previous owner changed it to R134 then there is nothing I should be worried about. The problem is, HOW CAN I TELL IF IT WAS CHANGED to R134?

If the R12 system was not converted to R134. WHAT DAMAGE HAVE I DONE and WHAT SHOULD I DO?

PLEASE HELP!

__________________
1991 420SEL Project Car (Completed and rides beautifully) http://www.peachparts.com/shopforum/showthread.php?t=112321
2000 BMW 740IL
2000 Integra Type R - Track Car - SOLD
2005 S2000 - Track Car
06 C230 Sport
89 560SL

Short of having a refrigerant identifier instrument, you cannot know for sure if you don't know the history of the car. By US Federal law, the car is SUPPOSED to have the correct fittings, but zillions of cars get converted to all kinds of refrigerants without changing fittings.

Yes, you can put 134 in a system and it will likely cool great. The problems will occur later. Depending on the conversion even one that is considered to be converted correctly is almost sure to have problems in the future.

R12 has come down in price and 134 is going up. There is very little difference now, in the price of the two. If the car were mine, I would break all connections and flush everywhere to get all the oil and any debris that might be present out of the system, replace the r/d, put in about 8 ounces of mineral oil, evacuate it and then charge with R12. That is the only way you will have a system with a good chance of staying in good shape for the long term.

If you insist on staying with 134, please do it legally with a sticker, the correct fittings and make sure it has the correct amount of ester oil and has been properly evacuated.

Good luck,

The A/C connections are completely different, R12 are screw on while R134 are push on, like air tools. There should also be a blue sticker somewhere on an A/C component, like the accumulator, detailing the conversion date.

Look at the A/C refill connectors first.

__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

I suppose that I was not clear in my previous post.

There are ZILLIONS of cars out there with original R12 fittings, no adapter fittings and no sticker that have 134 and all kinds of other refrigerants in them. This violates US Federal law, but they're plenty of them out there.

The only way to know for sure is to connect a refrigerant identifier instrument. DO NOT assume that it is R12 because there are R12 fittings on it.

Now that 134 is going up in price the same now holds true for a car with 134 fittings. There could be anything in there.

The people who are to be thanked for this are those who are either ignorant of the law or choose to break it.

Have a great day,