TM   5-2815-241-34&P INSPECTION  -  CONTINUED OIL  SEALS Inspect feather edge of oil seal for hardness or cracks. Metal-encased oil seals should not be re- placed  unless  inspection  indicates  damage. CORE HOLE PLUGS Inspect core hole plugs for evidence of leakage. Replace if damaged or if leakage is evident. REPAIR The procedures for repair will be similar for most components and parts that make up the engine. Any repair procedure that is peculiar to a specific part or component is covered in the paragraph relating to the item. After repair, clean all parts thoroughly to prevent metal chips or abrasives, that may accu- mulate during repair, from entering moving parts of engine. CASTINGS 1. Replace  all  cracked  castings. 2. Replace  all  castings  that  do  not  meet  specifications  given  in  paragraph  relating  to  that  item. 3. Repair minor damage to machined surfaces with a fine file, emery cloth (item 1, appendix B), or crocus cloth (item 4, appendix B) dipped in drycleaning solvent (item 16, appendix B). Replace all castings with machined surfaces burred or nicked so badly that, after milling or grinding,  they  still  will  not  allow  proper  assembly  or  operation. 4. Repair minor warpage of mounting flanges and gasket surfaces by moving the surface across a sheet of emery cloth (item 1, appendix B) held tightly on a surface plate or similar flat surface. Finish with crocus cloth (item 4, appendix B). Replace castings with flanges warped so badly that  they  will  not  allow  proper  assembly  or  operation. NOTE Pipe plug threads in castings must be in good condition to prevent oil or water leakage. 5. Repair damaged pipe plug or screw threads in tapped holes by using the appropriate tap. BALL   BEARINGS 1. Replace all galled, pitted, or damaged bail bearings. 2. Replace all ball bearings that do not meet specifications given in paragraph relating to the part in which  they  are  installed. 3. Refer  to  TM  9-214  for  maintenance  of  bearings. 2-6