Cylinder Head - Rebuild (2-02) Section 2 - Cylinder Head - Group 02 M11 Page 2-12 Use magnetic crack detector, Part No. ST-1166, to find cracks in the combustion face, in areas around the valve ports and the injector bores. Place the magnetizing head on the combustion face as shown, to check for cracks that run across the cylinder head. Fill the powder spray bulb one-third (1/3) full with metal powder. Spray the powder lightly onto the combustion face. Use compressed air to remove the excess metal powder. Air Pressure: 276 kPa [40 psi] NOTE: The powder will remain in the cracks, if present, and show as a white line. Visually inspect the cylinder head for cracks in the com- bustion face.
If any cracks around the injector bore are longer than 7 mm [0.250 inch], the cylinder head must be replaced. Both ends of a crack between the valves must be visible. If one end of a crack extends into the valve seat insert bore behind the valve seat insert, then the condition of the cylinder head is questionable. To be sure that the cylinder head is in good condition, remove the valve seat insert. Refer to Cylinder Head Valve Seat Insert - Replacement (2-04).