Hello All,

Recently purchased a 1989 300E. I've had it in a shop to have some work done to it (new radiator, hoses, shift bushings). While there asked mech to diagnose the A/C Unit.

When I picked the car up the mech informed me that the compressor had a little noise coming from it (nothing major), it did not have any leaks.

When I engage the A/C unit, the car doesn't act weird, but it only blows warm air (even in recirc mode).

Could it be as simple as the A/C Unit needing recharging, or should I look for other problem areas first? Also, during original production of this car (Northeast Region) which A/C format was used R12 or R134? I'm not sure which I have.

Thank you in advance for all replies to this thread.

Your car should be R-12, unless it was converted to R-134A. You will to connect a set of A/C gauges to monitor the system, make sure the compressor is turning, and look at the sight glass on the dryer/receiver to see if it is clear or if it has bubbles.

Good Luck,

D Cameron

Thanks for the speedy reply. With R12 so old now, are there still shops around that can service these units especially since the general public no longer can do so?

My novice opinion is that the system is good and sound (again novice), but I will definitely keep all posted on the findings.

You should still be able to find a shop that has R-12, but it won't be cheap.

I just had a pound added to my car for about $90, which included shop labor at the dealership. I knew that the system only needed a recharge, but I wanted them to test and diagnose it while they had it. So one hour labor and one pound of R-12. They cautioned me about a potential system leak, but I've been noticing the system performance degrade over the last year, and the shop manual states that losing an ounce or two per year is normal. Pretty standard for them to add a UV dye these days to identify leakage too.

However, when is the last time that your system was operable? If you don't have any system pressure in it at all, you are looking at as a minimun replacing the reciever / dryer, vacuum drying the system, and (I think) two and a half pounds of R-12.

Good Luck

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