The oil pump is installed in the timing gear cover.
1. Drain the oil from the engine crankcase.
2. Remove the oil pan (see subsection 3.1).
3. Remove bolt 8 (see fig. Parts of the engine lubrication system 1.0 l, 37 kW and 1.4 l, 50 kW) fastening the receiver 20 of the oil pump to the cylinder block.
4. Remove the four bolts 19 securing the receiver 20 to the timing gear cover.
5. Carefully remove receiver 20 and pump gears 22.
6. Remove dirt and rinse the oil receiver mesh with white spirit. If the screen cannot be cleaned or is damaged, replace the oil receiver.
7. Pull out cotter pin 5 being careful not to pop out spring 7.
8. Take out the spring 7 and ball 6 of the pressure reducing valve.
9. Inspect the relief valve seat. There should be no burrs or deep scratches on its inner surface. Ball 6 must move freely in the socket. Otherwise, replace the oil receiver.
10. Install the gears in the timing gear cover. Put a metal ruler 1 and measure the gap between the ruler and gears 3 with a feeler gauge 2 (4 – a cover of distribution gears). The nominal axial clearance is 0.02–0.1 mm, the maximum allowable is 0.13 mm.
11. If the clearance exceeds the limit, replace the timing gear cover. If the gap is less than 0.02 mm, install the shim 21 (see fig. Parts of the engine lubrication system 1.0 l, 37 kW and 1.4 l, 50 kW).
12. Assemble the oil pump in the reverse order, having previously lubricated with engine oil the gears, gear axles, the pressure reducing valve ball and the mating surface of the oil receiver. The tightening torque of the oil receiver mounting bolts is 8 Nm.