Remove the valves (Inlet and Exhaust). 6. 7. Remove the valve guide. Inspection 1. Cylinder Head Checking Cylinder Head Mating Surface 1. Using a straight edge and feeler gauge, check evenness of cylinder head parting surface with crank case. If unevenness exceeds specified values, replace cylinder head. 2. Permissible unevenness of cylinder head mating surface-0.040 mm (Length wise) / 150mm. 3. Permissible unevenness of cylinder head mating surface-0.040 mm (Cross wise) / 150mm. 4. Overall flatness 0.1mm 2. Valves 1. Check valve leakages by pouring gasoline on valve head. Gasoline must not seep past valve seat. 2. Valves with burnt heads, excessive scoring and wear on stem should be replaced. 3. Check valve seat run out with respect to valve stem. If it exceeds specified limit replace valve. No attempt should be made to straighten bent valves. 4. If valve is free from any other defects except worn out seat, then only it can be rematched on valve grinding machine as follows: Clamp valve on grinding machine • Adjust grinding angle on graduated scale to • achieve correct valve seat angle. Feed valve slowly towards grinding wheel • until wheel just touches valve head. Grind at low feed until valve seat is just • clean all around. 3. Valve Guides 1. In case of valve stem sticking in valve guide bore or Excessive clearance between them, remove valve guide From cylinder head using drift (Part No.2868 5890 06 05). 2. Check the condition of valve guide oil seals. 3. Check valve guide bore diameter in cylinder head and if necessary, ream valve guide bore in cylinder head to next over size. 4. Install matching size valve guide in cylinder head using drift (Part No. 2868 5890 06 05) and spacer. SPECIAL TOOL Valve Spring Compressor -: 2868 5890 06 • 05 NOTE Cylinder head top and bottom surface • remachining in service is not permitted. NOTE After grinding, valve head thickness should • not be less than 0.85 mm. Diesel Engine Ph-2 (CAFÉ) 155
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