Common Hydraulic Problems of Vulcanizing Press and Maintenance Tips

(Suitable for ceramic rubber liner production, Alibaba / website English version)

1. Pressure drop / cannot hold pressure (most frequent for 45 kgf/cm² vulcanizing process) Reasons: aging cylinder seals, leaking hose fittings, poor sealing of check valve / relief valve, contaminated hydraulic oil. Suggestions: inspect all seals and O-rings; replace hardened or cracked seals; tighten leaking joints; clean or overhaul pressure-holding valves; change dirty or emulsified hydraulic oil.
2. Slow mould closing / ram moves weakly Reasons: insufficient oil level, clogged suction filter, pump wear, air trapped inside the hydraulic circuit. Suggestions: refill with specified hydraulic oil; clean or replace oil filter; bleed air repeatedly by lifting and lowering the ram several times; test pump performance.
3. Abnormal noise & vibration from hydraulic pump Reasons: cavitation due to blocked oil inlet, low oil level, pump bearing damage, oil viscosity mismatch. Suggestions: keep oil within normal level; clean suction strainer; use hydraulic oil of recommended grade; inspect pump bearings and coupling.
4. Hydraulic oil overheating Reasons: continuous overload, relief valve stuck in partial opening, oil contamination, poor heat dissipation. Suggestions: avoid long-time overpressure operation; clean relief valve spool; check cooling circuit; replace degraded oil.
5. Oil leakage at cylinder piston rod Reasons: scratched piston rod surface, dust ingress damaging seals, long-term seal aging. Suggestions: protect piston rod from abrasive dust; polish minor scratches; replace sealing kit regularly.
6. Pressure gauge reading unstable or inaccurate Reasons: gauge failure, air inside gauge channel, blocked pressure port. Suggestions: calibrate pressure gauge annually; drain air from gauge line; replace faulty gauges.

• Check hydraulic oil level, colour and cleanliness every shift.
• Replace hydraulic oil and filters according to service cycle (normally every 2000 working hours; shorter in dusty mining-related workshops).
• Inspect hoses, fittings and cylinder seals weekly for oil seepage.
• Keep hydraulic station clean; prevent dust, water and rubber debris entering the oil tank.
• Bleed air from the hydraulic system after oil change or long idle shutdown.
• Do not adjust relief pressure beyond the machine rated 45 kgf/cm².

✅ Common hydraulic faults

• Pressure loss & poor pressure retention
• Slow ram movement
• Pump noise and vibration
• Hydraulic oil overheating
• Cylinder oil leakage
• Unstable pressure gauge

✅ Maintenance tips

• Check oil level and quality daily
• Replace oil & filter periodically
• Inspect seals, hoses and fittings for leaks
• Bleed trapped air regularly
• Keep hydraulic station away from dust
• Never exceed rated working pressure

If you need, I can make a short safety warning paragraph for the hydraulic part.