As long as the inner wall surface with sand paper slip and check eddy leaves [or gear] whether there are cracks in the maintenance of hydraulic motors, any necessary replacement parts. Secondly also check whether the shaft deformation [curl]. If necessary the lathe Feasible would be best all bearing [or Carbon and copper] replacement. [remember every position during assembly should add a little oil up the hydraulic motor repair, while waiting for the inspection] last assembled by hand [or public with ] rotating shaft is smooth and it will be easier and smoother when the general rotation of the pump, but the pump will be more difficult [when it feels like when tight not tight] # Key: After the assembly, if not necessarily smooth again repeatedly checking hydraulic pressure. (liquid pressure) is generated by the pump. There are a variety of pumps: vane pumps, gear pumps, screw pumps, piston pumps, ....... There are a number of different structures in each type. You ask piston pump, there are multiple styles, structures. The radial, axial, single plunger multi plunger, ....... They have one thing in common: The plunger plug in the hole, the plunger reciprocates in the hole, (the same as the bellows), oil, drain. Put the pressure of pressurized oil into the oil. Acting hydraulic motors, hydraulic motors, hydraulic pressure from Jinan Jing Jing Chong Chong Hydraulic Machinery Limited. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) strong, credible, in Jinan, Shandong mining machinery industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead crystal create hydraulic and you hand into the brilliant, for a better future!