That's also a good theory. The pressure of the water against the condenser caused it to crack. Its like running into a wall of water deforming the condenser. Still, the thermal shock theory still makes sense. We're not just talking about a little rain, but a sudden immersion in water that is perhaps 180 degrees less than operating temperature. Anyway, if the condenser is firmly attached to the frame, could the water cause enough pressure to cause it to leak?

The condenser is alloyed aluminum....there is no way thermal shock of even 200 degrees F differential will cause the condensor to crack.

Imagine if aircraft had the same problem !:eek:
You'd have oil and water everywhere.

The pressure of water against the hoses alone would be enough to bend them back and strain the condenser fitting.

Rain water can and does have temperatures of just above freezing point even in Texas summer time.

Driving through a southern Texas rain storm in 110 degree weather with the a/c running would kill every a/c unit on the road if the cold water theory stood up.


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You've convinced me. Now I'm going to have to ask the mechanic specifically where the leak was. I was told by the service writer that the leak was in the rear of the condenser (facing the radiator). If it was around a fitting then you solved the mystery (for me anyway). However, I was not told it was around a fitting. Thanks for your patience in explaining the answer.

Serpentine belt
 

My a/c was working intermittently on my '91 300d. They finally found the dampner and idler pully were a bit warped, due to be changed, and they recommended the serpentine belt be changed. They figured what might be happening, is that the belt, even though it was not loose to the eye, might be skipping just a bit. They said if it slips just a tiiiiiiny bit, it will shut the a/c off. I had the repairs done, and a/c works fine now.

They also said to make sure the belly pan is on (the thing at the bottom of the engine to catch fluids). They said it keeps water off all the electrical stuff, as well as keeps road noises down.

Good luck.

I do agree with the water pressure against the condenser. that is more likely what happened as opposed to the thermal shock. I still believe that sudden changes in temperature dramatically weakens joints and structures, but the huge amount of water pressing against the condenser is probably a better explaination in this situation.

dkvuro is right !! I am from India, where temperatures in some parts in summer reach well over 100 d F. Car airconditioning systems are very advanced here. I once hit a stray dog at 70 mph+, impacted on the front left of the car, which fortunately escaped without much injury. A few minutes later, the cabin temperature rose. We discovered that the air conditioning condensor had bent backwards onto the radiator, and a smal bolt from the radiator punctured the condensor.......Here, the insurance company HAD to pay up !! I don't buy the thermal shock theory !!