Could use some magic advice from the forum.

The a/c on my '87 124 wagon went out a few weeks ago. Was on a long road trip and the front seal on the compressor failed. It let all the oil out, with the result that the compressor seized.

I completely disassembled the system, flushed it thoroughly, used dry air to blow it all out, etc. Acquired a new compressor, dryer, expansion valve, and nice green neoprene o-rings.

Put it all back together and I have a massive leak at the expansion valve. Disassembled, cleaned, and inspected that area, but it still leaked after reassembly. Is there some magic trick that I'm missing? Any advice, tips, tricks, voodoo, etc. would be appreciated.

- Jim