The method of eliminating the insufficient pressure of the hydraulic system of the used mixer truck？

The method of eliminating the insufficient pressure of the hydraulic system of the used mixer truck

Whether the hydraulic pump of the used mixer truck can output hydraulic oil. If there is no hydraulic oil output, it may be that the steering of the pump is incorrect, the parts are seriously worn or damaged: the resistance of the oil suction pipe is too large (the oil filter is blocked, the oil viscosity is too large, etc.) or air leakage.

If the used mixer truck is a new hydraulic pump, it may be that the pump body has casting defects (shrinkage holes, sand holes, etc.), which make the oil suction chamber and the oil pressure chamber communicate, lose the oil pressure capacity, and the input power is insufficient, so that the oil delivery pressure of the pump cannot reach the work. Pressure, the pump shaft is twisted and broken, and no oil can be output.

If the hydraulic pump of the used mixer truck has oil output, you should check each oil return pipe and observe which part is leaking oil.If the oil return pipe of the relief valve overflows, the set pressure may be low.

At this time, tighten the pressure regulating spring of the relief valve. If the pressure does not change, it may be that the main spool of the relief valve or the poppet valve of the pilot part is stuck in the opening position due to dirt or corrosion; or the spring is broken and loses its function; Or because the damping hole is blocked by dirt, the oil output by the pump immediately flows back to the oil tank through the overflow valve. Remedy: The overflow valve should be disassembled and cleaned. Check or replace the spring to restore its working performance.

Is the relief valve working properly? If the used mixer truck is not normal, the used mixer truck may be that a valve in the pressure oil circuit is stuck with dirt or other reasons, and the used mixer truck is in the oil return position, resulting in a short circuit between the pressure oil circuit and the overflow circuit, or the pipe joint is loose, or Some valves in the pressure oil circuit have serious leakage, or the seals of hydraulic cylinders and hydraulic motors are damaged, causing serious leakage. Remedy: disassemble the relevant valve for cleaning, check the size of the sealing gap and various sealing devices, the used mixer truck and replace the damaged sealing device.

If the output flow of the hydraulic pump decreases significantly as the pressure rises, and the pressure does not reach the specified value, the used mixer truck is because the clearance increases after the hydraulic pump is worn. Elimination method: Determination of the volumetric efficiency of the hydraulic pump can determine whether the pump can continue to be used, and parts that are severely worn should be repaired or replaced.

If the entire hydraulic system of the used mixer truck can establish normal pressure, but there is no pressure in some pipelines or hydraulic cylinders (or hydraulic motors), it may be because the pipelines, small holes or throttle valves, reversing valves and other parts are blocked. At this time, the pressure and whether there is oil passing through should be checked section by section, and the cause should be found and eliminated. If the hydraulic system pressure of the mixer truck is not enough or there is no pressure at all, the used mixer truck the used mixer truck can be checked and solved according to the above methods, so that the mixer truck can return to normal in time.