TM 9--2815--247--34 0012 00--2 GENERAL MAINTENANCE INSTRUCTIONS -- CONTINUED 0012 00 CLEANING INSTRUCTIONS -- CONTINUED Oil Passages Particular attention must be given to all oil passages in machined parts. All oil passages must be free of obstruc- tions. CAUTION Use care not to force probes into passage ways. Failure to comply could result in equipment damage. Clean passages with probes fabricated from 0.12 inch (3.1 mm) brass welding rods to break up all sludge or gum deposits. WARNING Wash passages by flushing with dry--cleaning solvent (item 5, WP 0100 00). Be sure passages are free from ob- structions and remove any particles which might later become dislodged and contaminate the oil system. WARNING After cleaning, dry passages with compressed air. Electrical Cables and Flexible Hoses CAUTION Do not use dry--cleaning solvent or mineral spirits paint thinner on rubber components and flexible hoses. Pro- longed contact with these cleaners cause leather, rubber, and synthetic materials to dry, rot, and lose pliability, making them unserviceable. Clean cables and flexible hoses with soap and water. Ball and Needle Bearings Bearings require special attention in cleaning and oiling. After removing the surface dirt, oil, or grease, the bear- ings, except the sealed, permanently lubricated type, should be placed in hot oil (about 150°F (65°C) to loosen con- gealed oil and grease. After cleaning, the bearings should be wrapped tightly in oiled or waxed paper until inspec- tion and assembly.