Rebuilding an injector pump requires a few basic steps. First, the existing pump must be disassembled to reveal the internal components that are in need of repair or replacement. Depending on the model and severity of damage, certain parts may be easy to identify as needing attention while others may require further inspection under a magnifying glass. Injector pumps contain several small pieces that can easily become lost during disassembly, so it's important to take care not to let any items slip away. Once all parts are accounted for and labeled, each component should be carefully cleaned with either warm, soapy water or solvent cleaner prior to reassembly. All seals should also be inspected for tears or other damage. If any of the seals are damaged, they should be replaced before reinstalling the pump. Once all components are properly cleaned and inspected, it's time to begin reassembling the injector pump. Each seal is fitted into place before inserting and securing bolts in their designated spots. A torque wrench is used when bolting parts together as this ensures proper tightness without damaging components due to over-tightening or under-tightening. After everything is securely assembled, it's time for testing and adjustments. Typically, fuel injection pumps need to be tested at a qualified facility or repair shop with specialized equipment tailored for the specific make and model of vehicle.