Full explanation
Key system components: (1) HYDRAULIC PUMPS — axial-piston Parker, Sauer-Danfoss, Bosch Rexroth rated 200–300 bar; (2) HYDRAULIC CYLINDERS — ISO 6020-1 (MH1) or 6020-2 (MH2) standard, Hallite/SKF Polypack seals; (3) HOSES — DN10–DN20, SAE 100R2 to 2SN up to 350 bar, spiral 4SP-4SH for 400+ bar; (4) COUPLINGS — QRC (Quick Release Couplings) per ISO 7241-1 series A (B), ISO 16028 for flat-face (non-leak). Common Ukrainian issues: (1) non-original hoses with unverifiable SAE rating (buy only Gates, Manuli, Parker), (2) dirty oil — the main pump-failure cause, cutting life from 8,000+ h to 1,500–3,000, (3) over-filling during rebuild. Monitoring: temperature <85°C, stable pressure ±5%, no pulsation. Oil changes (ISO 46 or 68) every 1,000–1,500 engine hours.