Idiot proof? I would not say that. If the clip came off then make sure you thread it back in on BOTH sides good, through the plastic openings. Access is tight near the radiator hoses and it is possible to thread it in one side only. It happened to me. The hose went in but it was clipped on one side only. The hose seemed secure at the time but came off after a few miles. So double check.

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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.