In industrial fields such as hardware stamping, mold processing, auto parts manufacturing and precision forming, hydraulic presses, power presses and CNC machining centers are core equipment that ensure efficient production line operation. With the advantages of high pressure, strong stability and wide adaptability, hydraulic presses are widely used in various precision processing procedures. As a professional manufacturer of power presses, hydraulic presses and CNC machining centers based in Ningbo, Ningbo Goanwin Machinery Manufacturing Co., Ltd. has been deeply engaged in industrial machinery R&D, production and sales for many years, serving numerous manufacturing enterprises at home and overseas. Based on our front-line production debugging and after-sales operation and maintenance experience, most hydraulic press faults are caused by non-standard operation, insufficient daily maintenance and aging parts. Frequent equipment faults will reduce production efficiency, increase workpiece scrap rate, shorten equipment service life and raise operation costs. To help users solve equipment problems efficiently and standardize operation and maintenance, this article professionally analyzes the causes, troubleshooting steps and solutions of six common hydraulic press faults, and shares factory-standard maintenance skills to stabilize production and reduce equipment loss.
1. Insufficient Pressure and Weak Pressing (Top Common Fault)
Insufficient pressure and weak pressing are the most frequent faults of industrial four-column hydraulic presses and single-arm hydraulic presses. The typical symptoms include normal no-load operation, but failure to reach the rated pressure during loading stamping and forming, unqualified workpieces, and even complete operation failure in severe cases.
Core causes: First, long-term high-load operation wears internal parts of plunger pumps and gear pumps, reducing oil supply efficiency and failing to provide stable rated oil pressure. Second, relief valve jamming caused by dirt accumulation, fatigued springs and loose pressure adjustment leads to system pressure relief and pressure holding failure. Third, long-term unused deteriorated hydraulic oil with unbalanced viscosity and excessive impurities blocks oil circuits and hinders pressure transmission. Fourth, aging and worn oil cylinder seals and control valve seals cause internal system leakage and continuous pressure loss.
Standard troubleshooting methods: Start the equipment with no load, adjust the relief valve pressure slowly and calibrate the rated working pressure to eliminate improper manual adjustment. Disassemble and clean the relief valve, remove dirt from the valve core, replace fatigued springs and repair jamming faults. Inspect the hydraulic pump working condition; repair or replace original hydraulic pump parts in case of overheating, abnormal noise and insufficient oil output. Finally, troubleshoot internal leakage of oil cylinders and multi-way valves, replace aging seals, clean oil circuit impurities, replace deteriorated hydraulic oil, and complete load pressure test to confirm pressure recovery.
2. Hydraulic Press Oil Leakage Fault
Oil leakage is the most common visible fault of hydraulic presses, divided into external seepage and internal leakage, which seriously affects equipment service life and production environment. External leakage usually occurs at pipe joints, cylinder piston rods and valve body joints, causing hydraulic oil waste and workshop pollution. Internal leakage is a hidden fault without obvious traces, manifested as load sinking, continuous pressure attenuation and slow movement, which is easily ignored and will trigger severe equipment faults over time.
Main fault causes: Long-term alternating high and low temperature operation accelerates aging and hardening of oil seals and sealing parts; continuous equipment vibration loosens pipe joints and wears and cracks oil pipes; excessive impurities in hydraulic oil wear sealing contact surfaces; scratched and deformed cylinder piston rods damage sealing integrity; high oil temperature caused by cooling system failure accelerates seal aging and failure.
Professional solutions: For external oil leakage, inspect all pipe joints, sealing flanges and cylinder end covers point by point, fasten loose parts, and replace cracked oil pipes and aging seals. For hidden internal leakage, conduct load pressure holding tests, isolate oil cylinders and control valves section by section to locate leakage points accurately, and replace original matching piston seals. Filter and replace hydraulic oil regularly to reduce impurity wear and fundamentally lower leakage rate.
3. Excessive Hydraulic Oil Temperature and Overheating Alarm
The standard working oil temperature of industrial hydraulic presses is 30℃-60℃. Continuous temperature above 80℃ will trigger a high-temperature alarm, accompanied by slow movement, unstable pressure and weak pressing. Long-term high-temperature operation will burn out core precision parts such as hydraulic pumps and solenoid valves and greatly shorten equipment service life. According to Goanwin Machinery's operation and maintenance data, most overheating faults result from insufficient maintenance and non-standard operation.
Common inducements: Dust blockage in hydraulic radiators and cooling fans reduces heat dissipation efficiency; insufficient hydraulic oil level leads to poor system circulating heat dissipation; long-term overflow of relief valves converts pressure loss into heat energy; long-term overloaded and high-frequency operation exceeds rated working conditions; mismatched hydraulic oil model and abnormal viscosity increase operating resistance and high temperature.
Troubleshooting and optimization methods: Stop the machine immediately for natural cooling, thoroughly clean dust from radiators and cooling nets, inspect cooling fan operation, and repair or replace faulty fans. Check hydraulic oil level and quality, and supplement original matching hydraulic oil. Recalibrate relief valve pressure accurately to avoid long-term overflow. Standardize operation and prohibit long-term overloaded operation. Replace suitable hydraulic oil according to workshop working conditions and seasonal temperature to reduce system resistance and stabilize oil temperature.
4. Stuck Movement and Lifting Failure of Hydraulic Press
This fault directly delays production progress, manifested as jittery lifting, delayed movement and unsmooth start-stop of the hydraulic press slider. In severe cases, the crossbeam cannot lift and button operation is unresponsive, resulting in equipment shutdown. Common problems include one-way descending failure, no movement and unstable lifting speed, mostly caused by dual faults of electrical system and oil circuit.
Fault causes: Abnormal electrical system including unreset emergency stop button, thermal relay overload protection and damaged misplaced limit switches; burned solenoid valve coils and oxidized contacts cause abnormal control signal transmission; blocked oil filter elements and pipeline dirt hinder hydraulic oil circulation; insufficient guide rail grease causes mechanical jamming.
Troubleshooting and repair methods: Prioritize electrical system inspection, reset emergency stop button, reset thermal relay, and replace damaged limit switches. Disassemble and clean solenoid valve contacts, detect coil voltage, and replace burned solenoid valves. Replace blocked filter elements, dredge oil circuits and replace dirty hydraulic oil. Refill guide rail grease regularly and debug slider operation accuracy to eliminate mechanical jamming completely.
5. Abnormal Noise and Vibration of Hydraulic Press
Sharp high-frequency howling, impact noise and intense body vibration during operation are typical faults of hydraulic systems or mechanical structures. Long-term faulty operation will accelerate part wear, reduce stamping accuracy and affect workpiece processing quality.
Core causes: Air entering the hydraulic oil circuit causes bubble compression and explosion and abnormal noise; insufficient oil absorption of hydraulic pumps leads to cavitation and high-frequency howling; loose fixing bolts and aging base shock absorption pads cause body vibration; worn and loose transmission parts such as bearings and gears.
Effective solutions: Open the hydraulic system exhaust valve and run the equipment with no load to exhaust air from the oil circuit. Inspect the tightness of oil suction pipelines, repair air leakage points and ensure smooth oil absorption. Fasten all equipment fixing bolts and replace aging shock absorption pads. Detect wear of transmission parts and replace worn parts in a timely manner to restore stable equipment operation.
6. Factory-Level Preventive Maintenance Skills for Hydraulic Press
According to our years of equipment operation and maintenance statistics, more than 90% of common hydraulic press faults can be avoided through daily preventive maintenance. As a professional manufacturer of hydraulic presses, power presses and CNC machining centers, we recommend enterprises to establish a standardized equipment maintenance system: regularly check hydraulic oil level and quality, replace hydraulic oil and clean oil circuit filter elements every 3 to 6 months; inspect pipeline sealing daily and eliminate potential slight oil leakage hazards; clean the heat dissipation system regularly to ensure unobstructed heat dissipation; standardize operation procedures and prohibit overloaded and long-term no-load overflow operation; calibrate system pressure and inspect electrical components monthly to troubleshoot hidden faults in advance and reduce failure rate fundamentally.
Conclusion
Hydraulic press faults are mainly concentrated in three core systems: hydraulic system, electrical system and mechanical structure. Most faults are not sudden, but accumulated by long-term non-standard operation and insufficient maintenance. Enterprise operation and maintenance personnel can quickly restore equipment working condition by accurately identifying fault phenomena, locating core causes and troubleshooting in accordance with standardized processes. Adopting equipment from formal manufacturers, adhering to factory maintenance standards and standardizing daily operation are the core keys to extending the service life of industrial equipment such as hydraulic presses and power presses, reducing operation and maintenance costs, and ensuring efficient and stable production line operation.
