Initially one should mark the position of
Timing Chains and then remove the timing chain sprocket from the crankshaft. Then, take out the oil pump retaining bolts and then gently move the oil pump to the end of the crankshaft. It follows that removal of the timing chain guide off of the oil pump housing together with the oil pump cover also enables pulling out of the rotors off the pump body. Lift off the snap-ring on the side of the pump housing and replace the cap/spring/plunger assembly which is the oil pressure relief valve. Remove any parts from the structure and use solvent to clean them and ensure they are very dry then assess them for visible signs of wear or damages with special regard to the bolt holes on crankshaft sprockets these are prone to developing threaded holes, to identify such damages you have to rotate the crankshaft sprocket while observing the holes to confirm if any of the threads have been stripped. They have to be replaced if they are damaged, scored, or worn, including the gears of the oil pump; no individual parts are available for servicing. If reusing the oil pump, fit the parts of the pressure relief valve and the rotors to the pump housing, and the pump casing and then pour fresh Motor oil into the spaces between the rotors to make it ready for work, fit the final casing then tighten the nuts on the pump. Place the oil pump over the end of the crankshaft and position the flat surfaces of the crankshaft with those in the oil pump, set the pump to the block surface flat firmly. Slip the oil pump mounting bolts and then tighten them to the right torque as recommended by Engine manufacturers. The remaining part of the installation is the mirror process of the removal of the installation. Last but not least, just fill with oil/coolant if required and then start the vehicle and look for signs of oil/coolant leak and also inspect the oil in the pressure gauge.