Gear pump in use, often occur insufficient oil, or no oil pressure phenomenon. We do the following analysis of this failure to facilitate the troubleshooting of gear pump and maintenance. The specific phenomenon: (1) gear pump work slowly lifting, shaking or can not be improved when lifting; (2) bubbles in the fuel tank or tubing; (3) lift hydraulic system sends "jack, jack" sound; Start working device can be improved, work for a period of time after the oil temperature rise, then increase slowly or can not be improved; (5) gear pump can increase light load, heavy load can not be improved. Fault reasons: (1) the hydraulic tank oil level is too low; (2) did not use the hydraulic oil by season; (3) the inlet pipe was seriously blocked by dirt; (4) gear pump gear oil seal damage, the air into the hydraulic system; 5) Gear oil pump inlet and outlet joints or bent joints "O" ring damage, bending joints or bolts into or out of the nut is not tight, the air into the hydraulic system; (6) gear pump leakage, The seal ring aging; (7) Gear pump end or main, driven gear sleeve end surface wear or scratches, two bushings end surface roughness unevenness; (8) gear pump internal parts assembly error caused by internal leakage; (9) Left-handed "installed" right-handed "pump, causing damage to the frame seal; (10) gear pump hydraulic oil is too dirty. : Gear pump information gear pump products