5.6 Disposal of used oil or fuel................................................28 5.7 Periodic Maintenance instructions....................................29 5.7.1 Check air filter.........................................................29 5.7.2 Cleaning air filter.....................................................30 5.7.3 Replacement of engine oil......................................30 5.7.4 Replacement of oil filter..........................................31 5.7.5 Cleaning of oil gas separator..................................32 5.7.6 Replacement of fuel filter........................................32 5.7.7 Air bleeding from fuel system..................................33 5.7.8 Adjustments and replacement of V-Belt..................33 5.7.9 Arrangement of cylinder head and valve.................34 5.7.10 Adjustment of valve clearance..............................34 5.8 Maintenance recommendation.........................................36 SECTION - VI Specifications for Lubricant, Coolant and Fuel......................44 6.1 Lubricant...........................................................................44 6.1.1 The functioning of lubricating oil in a diesel engine.44 6.1.2 Engine oil consist of................................................44 6.1.3 Why oil to be drained?............................................44 6.1.4 How engine oil performance getting deteriorated...44 6.1.5 Oil performance classification system.....................45 6.1.6 SAE viscosity recommendations.............................45 6.2 Engine oil recommendations for Weichai engines............46 6.3 Grease Recommendations...............................................47 6.4 Fuel oil recommendations.................................................47 6.5 Coolant.............................................................................50 6.6 A good coolant should have following properties..............50