TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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CHAPTER 6 OVERHAUL OF ENGINE COMPONENTS Section l. GENERAL CLEANING, INSPECTION, REPAIR, AND ASSEMBLY PROCEDURES 6-1. General a. Procedures. The procedures for cleaning, inspection, repair and assembly of the various parts and components which make up the engine subassemblies will be the same for a great percentage of parts and components. To avoid repetition, the general procedures are detailed in paragraphs 6-2 through 6-6 and will be referenced throughout this chapter. Any cleaning, inspection, repair, and assembly procedures which are peculiar to a specific part or component will be covered in the section or paragraph relating to that item. Aluminum castings must be realodized or coated in ac- cordance with MIL-C-5541A whenever coating is marred. b. Tables will be used to list the various operations and components involved in the overhaul of engine sub-assemblies. Paragraph and / or figure references for disassembly, cleaning, inspection, repair, and assembly procedures will be listed in these tables under their appropriate heading. c. The Repair Parts section of the manual. Appendix B, will be used to identify parts and to locate points of measurement for overhaul limits. 6-2. Cleaning Instructions a. General. The importance of cleaning must be thoroughly understood by maintenance personnel. Great care and conscientious effort are required in all cleaning operations. The presence of dirt or foreign material is a constant threat to satisfactory engine operation and maintenance. A dirty operation can result in cylinder scuffing or scratching, high oil con- sumption, bearing destruction, and a variety of component failures directly attributed to the entrance of dirt. Maintain rigid cleaning standards during all phases of the cleaning operation. The following general instructions apply to all cleaning operations. (1) Clean all parts before inspection, after repair, and before assembly. (2) Hands should be kept free of any ac- cumulation of grease, which can collect dust and grit. (3) After cleaning, all parts should be cov- ered or wrapped to protect them from dirt and dust accumulation. b. Castings. (1) Remove sludge and gum deposits using a stiff brush. (2) Clean all surfaces with dry-cleaning solvent or mineral spirits paint thinner. Repeat operation if surface is not free of scale or adhering material which might be dislodged later. (3) Blow out all tapped holes with com- pressed air. (4) After cleaning, dry casting with com- pressed air. Warning: Particles blown by compressed air are hazardous. Make certain air stream is directed away from user and that other persons are not exposed. Protect eyes and face with appropriate shields. c. Oil Passages. Particular attention must be given to all oil passages in machined parts. All oil passages must be free of obstructions. (1) Clean passages with wire or probes to break up all sludge or gum deposits. (2) Wash passages by flushing with dry- cleaning solvent or mineral spirits paint thinner. Be sure passages are free from obstructions and clear any particles which might later become dislodged and contaminate the oil system. (3) After cleaning, dry passages with compressed air. d. Electrical Cables and Flexible Hoses. Clean cables and flexible hoses with soap and water. Note. Do not allow dry-cleaning solvent or mineral spirits pain thinner to be in prolonged contact with the rubber components and flexible hoses. These cleaners cause leather, rubber, and synthetic materials to dry, rot, and lose pliability, making them unserviceable. 6-1