If you are going to use the tool every day as a professional then buy the best one you can afford. if you are doing it once or twice or year then a cheap VP is good enough. You don't need the best vacuum for A/C to work. I used to use the Venturi VP ( $12 ) pump with a compressor to do A/C work at home. never failed. I would recommend to replace the rec/driver every time you open up the system.

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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.