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Common Problems and Solutions for Lift Pumps and Cylinders
2026-04-09
1 Insufficient Pump Pressure, Slow Lifting, Failure to Lift
Causes: Air in the pump; Worn seals, internal leakage; Worn/jammed check valve; Insufficient oil, thin/dirty oil
Solutions: Bleed air by lifting and lowering repeatedly; Replace repair kit (oil seal, O-ring); Clean or replace check valve ball/seat; Refill or replace hydraulic oil
2 Manual Pump Rebounds, Feels Soft When Pressed
Causes: Poor seal of check valve; Oil outlet pressure relief; Damaged internal oil seal
Solutions: Replace check valve assembly; Check if connectors are loose or leaking; Replace pump repair kit
3 Electric Pump Not Working / Motor Runs but No Lifting
Causes: Burnt motor, blown fuse; Worn gear pump; Relay/switch failure; Clogged oil circuit
Solutions: Check circuit, fuse, relay; Replace pump core/gear pump assembly; Clean filter and oil circuit
4 Oil Leakage (Pump Body, Connectors, Motor)
Causes: Aging oil seal; Loose connectors; Cylinder body cracks
Solutions: Replace oil seal; Tighten connectors; Replace pump assembly if severe
1 Oil Leakage (Most Common)
Positions: Oil seepage at piston rod, oil leakage at both end caps
Causes: Worn, cracked oil seal; Scratched piston rod, chrome layer peeling; Eccentric installation, uneven force
Solutions: Replace oil seal repair kit; Replace cylinder if piston rod is severely scratched; Adjust installation position to avoid jamming
2 Weak Lifting, Fast Descending, Automatic Sliding Down
Causes: Internal cylinder leakage (damaged piston seal); Failed check valve
Solutions: Replace piston seal; Check oil circuit check valve
3 Lifting Stuck, Abnormal Noise
Causes: Impurities in the cylinder; Lack of oil; Misaligned installation
Solutions: Clean and change oil; Adjust installation angle
4 Cylinder Deformation, Bending
Causes: Overload; Impact; Poor material quality
Solutions: Replace directly, cannot be repaired
1 Cab Stops Halfway When Lifting, Cannot Descend
Causes: Air not fully bled; Pressure relief valve cannot open; Clogged oil circuit
Solutions: Bleed air again; Clean pressure relief valve; Unclog oil pipe
2 Difficult Lifting in Cold Weather (Cold Car)
Causes: Hydraulic oil viscosity too high
Solutions: Replace with low-temperature hydraulic oil (ISO VG32)
3 New Pump and Cylinder Still Not Working After Installation
Causes: Old oil circuit is dirty, impurities enter new pump and cylinder
Solutions: Must clean oil tank, oil pipe and filter before installing new products
