a) The oil level is too low or the wrong hydraulic oil is being used. b) The oil filter is clogged. c) Air enters the hydraulic system. d) The pump oil seals are seriously worn and there is serious leakage. e) The main control valve is stuck. f) The main control valve is seriously worn. g) The safety valve is broken. h) Serious cylinder leak. i) Leakage in distributor seals.
a) Add or replace with proper oil to the specified level. b) Wash the filter. c) Remove air from the system and tighten the connecting pipes or replace the seals. d) Replace the pump oil seals. e) Operate the lift control lever several times and switch the main control valve with a screwdriver; If the valve still sticks after this, remove and wash it clean. e) Replace the worn one. g) Repair or replace the safety valve. h) Replace seals or worn parts if necessary. i) Replace the seals.