Mechanical Fuel Pump Testing (page 2) ↗
Testing and reviving the Pierburg mechanical fuel pump on carbureted M30 E3/E9 cars. Tips: rule out air leaks in old hoses and add a check valve, check delivery into a jar while cranking, and when rebuilding, tighten the diaphragm with the pump mid-stroke. Gives the rebuild kit number (13311255184, likely NLA) and the E9 pump number.
Tools mentioned: Screwdrivers, fuel hose, check valve, jar
Thread is in the E3 sedan forum; pump and kit numbers quoted in posts.