Quick Answer The decision is not really "assembly versus parts" — it is "what kind of failure do you have?".Internal parts make sense when the damage is confined: a seal weeping, one identifiable item worn, and the rest of the pump still measuring within specification.A complete assembly makes sense when the damage is widespread or unknown: metal has circulated, several working surfaces are ...

Quick Answer When a SANY SY500 travels slowly on one side only, the symptom itself is the most useful clue you have: it rules out everything that serves both tracks. The fault must be in one track's circuit or one track's final drive. The decisive test is simple and costs nothing — swap the travel hoses left to right. If the slow side follows the hoses, the problem is hydraulic (relief, cont...