| • | A damaged or rough pump shaft bearing | 
| • | Casting porosity | 
| • | Interconnected oil passages | 
| • | Damaged machined surfaces | 
| • | Foreign material | 
| • | Cut seals | 
| • | Bent connectors or broken wires | 
| • | Cracked or damaged plastic housings | 
| • | Foreign material | 
| • | Wear | 
| • | Nicks | 
| • | Scratches |