Oil Pumps on the market are divided into original parts,branded aftermarket parts,refurbished parts,and inferior imitation parts,with significant price differences.The oil pump is a precision component that affects the life and death of the engine.Poor quality oil pumps do not show any problems in the early stages of installation,but after working for dozens of hours,the pressure decreases,causing major engine repairs.Mastering simple identification methods can avoid quality traps.

　　Firstly,let's take a look at the appearance of the casting process.The high-quality oil pump housing is cast flat,without air holes,sand holes or shrinkage holes,and the rotor and gear are processed smoothly without burrs.The sealing surface is flat and the screw holes are regular.Poor quality imitation oil pump housing has many sand holes,rough rotor edges,poor machining accuracy,inadequate control of internal clearance,and rapid pressure relief after use.The refurbished oil pump casing has been polished and repainted.Upon closer inspection,old wear marks and scratches can be seen on the casing.The pressure limiting valve spring is an old part and its elasticity has weakened.

　　Secondly,the rotational feel can be manually tested.Rotate the oil pump drive shaft by hand,and the genuine product rotates smoothly and evenly without any jamming or obvious looseness.There are no lagging points during the rotation process,and the meshing clearance of the rotor gears is uniform.Poor quality parts may experience stuttering or significant radial clearance,resulting in excessive internal clearance.During operation,oil may flow back from the clearance,making it difficult to establish stable oil pressure.

　　Then check the pressure limiting valve components.The genuine pressure limiting valve core slides flexibly,the spring elasticity is uniform,and the thickness and length of the spring are consistent with the original factory standard.Poor quality products with spring stiffness that does not meet the standard are prone to premature pressure relief or pressure relief failure,resulting in uncontrolled pressure in the oil system.Upon disassembly and observation,there are signs of wear and corrosion on the valve core,most likely indicating that it is a refurbished part and cannot be installed on the vehicle.

　　If possible,a simple stress test can be conducted.Connect the oil pump to a simple testing fixture,add engine oil,rotate the drive shaft,and observe the oil flow rate and pressure.The qualified oil pump speed increases,and the oil pressure synchronously and steadily increases;Poor quality oil pumps have low oil flow rates,inability to increase pressure,and large pressure fluctuations.Ordinary construction sites do not have fixtures,so the focus is on comparing weight,workmanship,and rotational clearance.

　　Don't blindly pursue low prices.Many low-priced oil pumps from subsidiary factories have realistic appearances,but the internal rotor material is poor and prone to wear and tear.For mining and long-term continuous operation equipment,try to choose original or legitimate brand oil pumps.Old excavators should also reject defective refurbished parts.The oil pump accessories themselves are not expensive,but they cannot afford the engine overhaul losses caused by vehicle failure.Quality identification must be rigorous and meticulous.