The hand pump, I may be wrong here but I believe it's in the same place as it is on my W115 chassis. If it's not on the injection pump as the previous post suggested then try looking at the FUEL FILTER. It will not be the "cylinder" shaped pump like on the W123 series. It will be more of a saucer shape. Mine has a black pump and a metal base. It is mounted on the drivers side of the engine compartment near the front of the engine and it is attached to the filter housing. It has a line coming to it from the Injection pump. Hope this helps! Tom

BTW, I had trouble finding mine too as the plastic "top" piece that you "pump" was MISSING. That's right it was broke right off!