Before any operation of the removal of the oil pump assembly, connect the cable with the negative terminal from the battery and then lift the vehicle and place on jack stands. Go on to the oil pan and pick-up tube/strainer then take off the timing belt and crankshaft sprocket. Remove the centre bolts and remove the oil pump assembly from the crankshaft. If the pump does not come off easily loosen the remaining bolts and then gently tap or pry on a casting boss. Disconnect the mounting screws and the cover can be slid off; the inner and outer rotor requires removal from the body-be careful because erosive wearing is vital for oil pressure; otherwise, one has to replace the complete pump. Some applications require removal of the crankshaft to access the front seal within the oil pump body; if so, replace as necessary. It is recommended to clean all components with solvent, this makes the analysis and estimation of excessive wear or any damage easier. Remove the bolt and washer, and take off the spring and valve which is located in the head of the relief valve. Examine the piston sliding surface and the valve spring; both of these should set should be replaced as a set if they are worn. The grooved end of the valve must be placed first during reassembly, apply oil, and place back to the pump body then use the cap bolt and tighten. Make use of the micrometer and feeler gauge to gauge the clearance in the oil pump components. For installation one needs to lubricate the housing and the rotors with clean engine oil, fit both rotors and fasten the cover with the screws. Immerse the oil pump in clean engine oil and lubricate the O-ring located in the oil discharge passage, the oil pump body is then sealed and connected to the block using bolts to the required torque. If it is an interference engine install the crankshaft sprocket and timing belt, pick-up tube/strainer assembly and oil pan. Last, put a new oil filter and engine oil, start the vehicle, inspect for the oil pressure and leakage and, inspect the engine oil level again.
