SAFARI

ENGINE 79 Fig. 8 Fig. 9 Fig. 10 Fig. 11 PRESSURE TESTING OF CYLINDER HEAD 1 Thoroughly de-grease, descale and clean cylinder head. 2 Firmly screw on steel plate with rubber pads on cylinder head. Block one outlet of upper cooling line and connect water hose to other outlet. 3 Connect other end of water hose to a hand operated water pump dipped in a container of hot water preferably at 70 deg C to 80 deg C. 4 Test cylinder head for cracks/leakages with water under a pressure of 5 bar. Fig. 8. 5 Alternatively, dip cylinder head along with sealing plates in a tank containing water at 70 deg C to 80 deg C and connect hose to a compressed air line. Pass compressed air at 5 bar and check cylinder head for leakage/cracks. 6 Replace cylinder head having any cracks. NOTE : Do not remove the lower protective sleeve. If it is removed for any other purpose install it back with new sealing washer and apply recommended thread locker and specified torque. INSPECTION AND REPAIR 1 Check cylinder head surface with a straight edge and feeler gauge, for unevenness (lengthwise and crosswise). Fig 9 and 10. 2 If necessary, grind this surface just to clear the unevenness. Ensure that specified machining tolerance is not exceeded. 3 In addition to total cylinder head thickness observe that the water jacket thickness at parting surfaces must not be less than 6 mm. 4 After reconditioning of parting sur faces by grinding, measure distance between valve head and parting surface Fig. 11. Refinish valve seats, if required.