1 check the hydraulic pump is not the normal condition, the hydraulic pump is usually equipped with a regulator, auxiliary valve or an oil pump, auxiliary valve or a auxiliary hydraulic pump, so it is difficult to find the cause of the failure.
2 check the following main components to identify any abnormalities:
1) check whether the filter element has abnormal impurities.
If there is aging of the foot and hydraulic cylinder, there may be a small amount of metal debris.
2. If there are too many metal crumbs, the toe part is damaged.
Similarly, check whether there is any oil discharged from the hydraulic pump housing.
2) check the abnormal sound or vibration of the hydraulic pump.
(1) check the release valve of the regulator if it is the sound of the regulator frequency.
If it is abnormal vibration or noise, it may be due to cavitation or internal damage of hydraulic pump.
3) check the oil road using two hydraulic pumps for two single hydraulic pumps or one double pump in which a hydraulic pump tube needs to be replaced with the other tube. The replacement result is that the fault is judged to be in the hydraulic pump itself and the downstream part of the hydraulic pump oil flow.
4) if the fault is a problem of control, there is no need to disassemble the hydraulic pump and check the pressure at different measuring points of the oil circuit.
5) wear limits of hydraulic cylinders, valve plates and swashplate. When a part exceeds the following criteria or obviously has serious damage, it should be replaced or adjusted.
Fig. 1-9 wear limit of hydraulic cylinder, valve plate and swashplate
The clearance between the D-d: piston and the hydraulic cylinder bore, the clearance between the 8: piston and the package foot.
Packing: the thickness of the package foot; the height of the hydraulic spring; the height of the H-h: setting plate and the spherical bearing bushing.
