First, the phenomenon of hydraulic pump failure and analysis
Hydraulic pump in the repair from the following three points to find the cause of the malfunction, and the system to improve:
Hydraulic pump failure reasons 1, check the boom cylinder leakage situation. The easiest way is to raise the boom to see if there is a clear free fall. If the whereabouts of obvious removal of fuel tank inspection, seals have been worn should be replaced.
Hydraulic pump failure reasons 2, check the control valve. First clean the safety valve , check whether the spool wear, such as wear and tear should be replaced. If there is still no change after installation of safety valve, and then check the control valve spool wear, the gap limit of use is generally 0.06mm, severe wear and tear should be replaced.
Hydraulic pump failure reasons 3, measuring the pressure of the hydraulic pump. If the pressure is low, then make adjustments, the pressure is still not adjustable, the serious damage to the hydraulic pump.
In general, the main reason that the boom can not be lifted is:
1, hydraulic pump serious wear and tear. The pump leaks seriously at low speed. When the pump runs at high speed, the pump pressure slightly increases, but due to the pump wear and leakage, the volumetric efficiency drops significantly and it is difficult to reach the rated pressure. Hydraulic pump work for a long time has exacerbated the wear and tear, oil temperature, resulting in wear and tear of hydraulic components and seals aging, damage, loss of sealing ability, hydraulic oil deterioration, and finally lead to failure.
2, hydraulic components selection is not reasonable. Boom cylinder specifications for 70/40 non-standard series, the seals are also non-standard parts, high manufacturing costs and seal replacement inconvenience. Boom cylinder bore is small, the system is bound to set high pressure.