The switch over valve prevents over boosting by the turbo. I do not know it location on the w126. On the w123 it's at the 10 to 11 o'clock position when looking att he brake booster.

The bowden cable is an actual cable tha has a ball joint end at the top side of the engine. It does have a socket end to fit the linkage on top of the valve cover.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D