As the core power source of hydraulic systems, the performance stability of hydraulic pumps directly impacts equipment operational efficiency. As hydraulic technology experts, Guangdong Haozheng Hydraulic Equipment Co., Ltd. emphasizes: when your hydraulic pump (especially precision plunger pumps) requires extended storage, professional maintenance is mandatory to prevent irreversible damage. Below is our standardized 20-year field-validated maintenance procedure.
5 Technical Reasons for Complete Oil Drainage
1. Fluid Contamination: System “Blood” Purification
Hydraulic oil accumulates metal particles and dust during storage. Our lab data shows:
- 300% average increase in >5μm particles after 1-year storage
- These contaminants accelerate wear in precision components (valve plates, pistons)
2. Oil Degradation: Performance Deterioration
Oxidized hydraulic oil exhibits:
- Viscosity variation >±10%
- Increased acid number (>0.5mgKOH/g)
- Reduced demulsibility We recommend regular testing with oil analysis equipment or direct replacement.
3. Moisture Corrosion: Silent Killer
Stored pumps are prone to condensation causing:
- Plunger pump bushing corrosion
- Bearing pitting
- Valve spool sticking Our case studies show unmaintained pumps have 5x higher corrosion failure rates.
4. Seal Aging: Preventive Replacement
Key inspection points:
- Shaft seals (replace every 2 years)
- O-rings (replace every 3 years)
- Cover gaskets (replace every 5 years) OEM seals last 30% longer.
5. Performance Recovery: Renewed Efficiency
After oil change:
- Volumetric efficiency recovers to >95%
- Noise reduces by 3-5dB
- Temperature rise decreases 10-15℃
Professional 5-Step Hydraulic Pump Preservation
Step 1: Complete Oil Drainage
- Operate pump for 3 minutes to reach 40-50℃
- Open all drain ports (including case drain)
- Blow residual oil with compressed air (≤0.3MPa)
Step 2: System Flushing
Use Guangdong Haozheng specialty flushing oil (ISO VG22):
- Plunger pumps: 30-minute flush
- Gear pumps: 15-minute flush Post-flush cleanliness: ISO 4406 18/16/13 standard
Step 3: Rust Prevention
- Fill with preservative oil (e.g., Shell Ensis)
- Manually rotate shaft 5-10 revolutions
- Seal all ports
Step 4: Storage Environment Control
- Temperature: 15-35℃
- Humidity: ≤60%RH
- Recommended: Use desiccant cabinets
Step 5: Pre-commissioning Check
Before restart:
- Install new filter (β≥200)
- Fill with specified hydraulic oil
- Run unloaded for 30 minutes
3 Expert Tips for Extended Service Life
- Regular Wake-up: Unloaded operation every 3 months (10 minutes)
- Oil Monitoring: Sample testing every 6 months
- Professional Service: Contact Guangdong Haozheng for customized plans
For high-value plunger pumps, we recommend smart monitoring systems for real-time storage tracking. For technical support or OEM maintenance kits, please contact our service hotline.
(Technical standards established by Guangdong Haozheng Hydraulic Equipment Co., Ltd. R&D Center. Please credit source when reposting. Refer to equipment manuals for specific operations.)