Hey guys, I'm replacing the AC condenser on my 2003 SL55. The original part has an inlet and outlet configuration like the first photo below. The used part I got off eBay has the pipes oriented differently, as shown in the second photo. I know the condenser has an updated part number, but what's the deal with the pipe orientation? The two hoses that connect to the condenser are too short and rigid to fit around anything.

 

I found these two on ebay. Same exact part # on condenser but different in/out orientation. Did Mercedes run out of #s for their parts?
Link
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The real question is does it matter much whether the top or bottom sides get the hotter fluid first?

 

I hope you're being sarcastic. It'd make my life a whole lot easier.

 

No. Engine radiators always direct the hot water to the top, but I have seen transmission and engine oil cooler direct the hot fluid to the bottom.
I don't think it would make much difference. This assumes your feed line fit properly and bolt in; if they do I wouldn't give it a second thought.

 

I actually replaced all of them. The radiator is working fine. My question is about the AC condenser. As far as I know, the way it works is that gas comes out of the AC compressor and enters the condenser from the top. The condenser then condenses the gas into a liquid. Gravity plays a role here, so the liquid has to exit from the bottom. I could be wrong though.

 

I called the most experienced mechanic at one of my auto shops, who then called a specialist at an A/C shop and they both concur that the top/down direction does not matter. While the condenser is on the low pressure side of the system, there is still plenty of pressure to force the Freon through, regardless of its state. Just like an oil cooler, it is simply cooling the Freon.
Of course, this assumes the connections fit properly, e.g. that the feed and return fittings are the same size.

 

Thanks @mrvedit for helping out. I did question the gravity part of what I read as well. It seems a bit dodgy for a car AC system to rely on gravity. Google also said that installing it backward could put pressure on the compressor and eventually damage it. I'm going to follow your advice. If, God forbid, the compressor fails, expect an invoice in your mailbox.

 

I remember them being the same size just by looking at them but I'm not sure. Will need to take a closer look.

 

The condenser's feed and return fittings are not the same size. Is welding an option to go from left to right?