I did not put any 'stop leak' in the AT. Do not know about the PO. The line is not 'disintegrating' so to speak. I was just puzzled by the slow leak and I am sure both ends are tightened as good as they can be. I have not removed them to inspect for any nicks at the joints ( radiator side, the pipe from the AT or the hose itself ). I think I will just replace them and be done with it.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.