Function: A fuel hand pump is a component of a diesel engine’s fuel system. It is used to manually prime the system, which means removing air from the fuel lines after maintenance, such as changing the fuel filter. Application: Similar hand pumps are commonly used for diesel engines, including those for trucks and other heavy machinery. The search results mention similar pumps for engines like the “6105 Engine” and “Yuchai YC6108 Engine”.   Errors & Omissions Excepted (E&EO