This workshop manual provides comprehensive technical information for the Lucas CAV N and NN Injection Pump. These inline diesel injection pumps are designed for mechanical fuel injection in various diesel engine applications. Known for their robust construction and reliable performance, the N and NN series pumps are integral components for efficient engine operation, featuring variable governor types and compatibility with various CAV nozzle types. This English-language manual is intended for workshop technicians and serves as an essential resource for maintaining and repairing the Lucas CAV N and NN Injection Pumps. It details critical procedures including disassembly, assembly, seal replacement, and calibration, utilizing specific diagnostic equipment such as the CAV-approved Hartridge service stand. Troubleshooting guidance is also included, ensuring technicians can effectively diagnose and resolve issues, making this manual a valuable addition to any workshop library.