The trimmer positioner is damaged, and the pressure is not changed and needs to be replaced.
The oil pump is damaged and the oil pump is worn inside and needs to be replaced.
Loosen the cylinder or tubing connector and check the cylinder for oil leakage. According to the type of rocker cutting machine, the oil of a rocker arm is from the bottom of the machine head and there is overflow on the upper side of the casing, which is convenient to see. The second type of rocker cutting machine needs to open the fuel tank cap to check whether the bottom of the cylinder is injecting oil. If it is determined that the oil leaks, replace the seal in time. There is very little chance of oil cylinder and cylinder plunger damage and oil leakage, and remember to check if the tubing joint is loose.
The temperature of the hydraulic oil is too high. For example, the use of the power supply suddenly becomes smaller, even without pressure. After a few hours of downtime, there was pressure to use it again, and then there was no use for a while. In this case, it is recommended to replace the hydraulic oil, remember to buy cheap hydraulic oil without greed.