This video should provide you a firm understanding of basic workings of a Roosa Master DB type fuel injection pump. I will walk you through the rebuilding process in detail from scratch to a complete pump. I'm not an expert. I however did much research before filming.
Thanks to yesterdaystractors.com and allischalmers.com where I received fantastic information. This pump is off my 1968 Allis Chalmers HD4. The pump and tractor sat for a decade and I am restoring her. The pump plungers and metering valve were seized as discovered in my first, less detailed video of the disassembly. Therefore no fuel was allowed to the injectors. In my next video I will reinstall the pump in an attempt to resurrect the Crawler.
My Roosa Master model number is: DBGFC 437-7AF
The Tractor: 1968 Allis Chalmers HD4 SN: +3001