Checking the technical condition and repair of the oil pump

Thoroughly wash all parts of the disassembled pump in kerosene or gasoline and blow with compressed air. If there are cracks in the pump housing or cover, replace them with new ones. Using a set of feelers, check the gaps between the teeth of the gears, as well as between the outer and inner diameters of the gears and the walls of the pump housing, which should be 0.15 mm and 0.11-0.18 mm, respectively. Maximum allowable gaps 0.25 mm. If the gaps exceed the maximum allowable values, replace the gears, and, if necessary, the oil pump housing.

Using a ruler and feeler gauge, check the gap between the ends of the gears and the plane of the housing, which should be 0.06—-0.16 mm (maximum allowable 0.20 mm). If the clearance is greater than 0.20 mm, replace the pump gears.

Measure the diameters and determine the clearance between the axle and the driven gear, which should be 0.017-0.057 mm (maximum allowable 0.1 mm), as well as between the pump shaft and the hole in the housing, which should be 0.016-0.055 mm (maximum allowable 0.1 mm). If necessary, replace worn parts with new ones. Permissible wear: axles of the driven gear up to a diameter of 11.90 mm, holes for the axle of the driven gear up to a diameter of 11.98 mm, holes in the housing for the pump shaft up to a diameter of 12.05 mm.

The surface of the pressure reducing valve and cover must be free of dirt and deposits, nicks and burrs that could cause the valve to stick.

Check the length and elasticity of the pressure reducing valve spring. The length of the spring in a free state should be 38 mm, and under a load of 6.35±0.2 kgf - 20 mm. If the length or elasticity of the valve spring is reduced, replace it with a new one.