When hydraulic equipment exhibits low pressure or excessive oil temperature, directly replacing pumps or valves rarely resolves the root cause. We recommend diagnostics following the principle: ‘external first, then internal; measure first, then disassemble.’
Common Causes of Low Pressure
- Inadequate suction: clogged suction filter, low oil level, or air leakage in suction line
- Overflow valve set too low or spool jammed
- Internal pump leakage: reduced volumetric efficiency due to wear
- Internal leakage in actuators: damaged cylinder seals
- Pressure gauge inaccuracy
Begin by verifying actual pressure at test ports, then inspect overflow valve and suction side—only proceed to pump disassembly if necessary.
Common Causes of Excessive Oil Temperature
- Clogged cooler or insufficient cooling water flow
- Continuous high-pressure overflow, causing parasitic heat generation
- Incorrect oil viscosity or degraded oil
- Oversized heat load relative to tank capacity or insufficient heat dissipation area
- Excessive pressure drop across piping
Simultaneously record ambient temperature, oil temperature, system pressure, and operating cycle to determine whether heating is continuous or action-specific.
Recommended Routine Maintenance
Regularly check oil level and condition; replace filters per schedule; keep coolers clean. Address pressure fluctuations or abnormal oil temperature promptly to prevent cascading damage to pumps and seals.
For on-site support or spare part selection, contact Liqiang Hydraulic.