1. Remove the oil pump from the car (see «Removal and installation of the oil pump»).
Note: If the sealing gasket remains on the pump housing and is not damaged, it can not be separated from the housing. In this case, when reinstalling the pump, lubricate the gasket with a thin layer of sealant.
2. Drain the oil from the pump.
3. Remove from body bore with any pointed tool (e.g. with a screwdriver) front crankshaft seal.
Pic. 5.14. Oil pump details: 1 - emergency oil pressure drop sensor; 2 - gasket for the emergency drop in oil pressure sensor; 3 - oil pump mounting bolt; 4 - front crankshaft oil seal; 5 - pump housing; 6 - safety valve; 7 - driven gear; 8 - drive gear; 9 - housing cover; 10 - cover fastening screw; 11 - body gasket; 12 - stopper of the reducing valve; 13 - plug gasket; 14 - pressure reducing valve spring; 15 - plunger; 16 - oil receiver; 17 - oil receiver mounting bolts; 18 - guide sleeve
4. Unscrew from the adapter of the oil pump housing the sensor B of the signal lamp for the emergency drop in oil pressure, and from the pump housing - the safety valve B and plug A of the pressure reducing valve. Remove the spring 14 from the housing cavity (pic. 5.14) and plunger 15 of the pressure reducing valve.
Warning: The relief valve spring is installed with an interference fit. Remove plug carefully to avoid injury.
Please note: there is a sealing gasket under the pressure reducing valve plug, do not lose it.
5. Turn out five screws of fastening of a cover of the pump...
6 - and remove the cover.
7. Remove the leading...
8 - and the driven gear of the pump.
9. Flush the pump housing and dismantled parts from dirt and deposits. Remove dense varnish deposits from the internal cavities of the pump by first softening them with a solvent.
Helpful Hint: Lacquer oil deposits can be easily removed with commercially available engine flushes (so-called «five minutes»).
10. Inspect the pump housing and cover. If there are cracks, scratches, casting defects, damaged threaded holes, replace the housing (because it is unrepairable) or pump assembly.
11. Check the pressure reducing valve plunger for scratches or sticking. Small dents and burrs can be removed with a fine grit sanding stone.
12. Check the pressure reducing valve spring for permanent deformation and bending. Replace damaged spring.
13. Check the gears for metal pitting, scuffing and tooth wear. Replace damaged gears or gears with noticeable increased one-sided tooth wear.
14. Check the axial clearance between the ends of the gears and the surface of the pump cover. This can be done in two ways.
15. In the first method, measure the thickness of the leading...
16.... and driven gears...
17.... as well as the depth of the bore in the housing for the gears. Calculate the axial clearance as the difference between the arithmetic mean of the boring depth and the thickness of the gears.
18. In the second method, install the driven gear into the housing, put a metal ruler (or caliper) end on the body and measure the gap between the body and the ruler with a feeler gauge.
19. Similarly measure an axial backlash of a leading gear wheel.
20. The maximum allowable clearances measured in both ways should be 0:045-0.100 mm for the driven gear and 0.035-0.085 mm for the drive gear.
21. Assemble the pump in the reverse order of disassembly. Before pressing into the pump cover, lubricate the front crankshaft oil seal with engine oil. Apply Loctite 573 or similar to the threads of the pressure reducing valve plug and tighten the plug to 30 Nm (3.0 kgf·m). If you install a new gasket 11 (see fig. 5.14), stick it to the body with grease.
Warning: Use only original factory gasket. Installing a gasket of a different thickness will cause the pump to malfunction. To avoid damage to the engine when starting for the first time after installing the oil pump, before installing the gears in the pump housing, fill the pump cavity with mineral grease to ensure that oil is sucked from the oil sump.
If at the first start of the engine with the oil pump replaced, the oil pressure does not immediately rise to the required level, immediately stop the engine, remove the oil sump and check the tightness of the connection between the pump and the oil receiver. If necessary, re-disassemble the pump and refill its cavities with grease. In the absence of the necessary pressure in the lubrication system, even a short-term operation of the engine leads to its emergency damage.