ARMY TM 9-2815-260-24 AIR FORCE TO 38G1-126-2 MARINE CORPS TM 09244A/09245A-24 3-15 Section V.  MAINTENANCE PROCEDURES 3.7. GENERAL. This section provides general maintenance not found in other sections of Chapter 3. __________ WARNING Where applicable, prior to performing engine maintenance, ensure batteries are disconnected to prevent serious injury or death. __________ WARNING Service tools are designed to aid disassembly and assembly procedures. Service tools must be used to prevent possible damage to components. Some operations can cause personal injury if carried out without use of relevant tools. NOTE Refer to TM 9-6115-672-14 for removal of any components necessary to gain access to engine. a.     All bolts or nuts securing cylinder heads, covers, and doors must be tightened in proper sequence. b.     When assembling an engine, always replace nuts, bolts, and lockwashers that have been removed from high stress locations such as from connecting rods and cylinder heads. c.     When assembling an engine always apply a small quantity of new engine lubricating oil (MIL-L-2104) to all moving parts. d.     After any maintenance work on engine has been completed lubricating oil and fuel levels must be checked and all safety guards installed before operating. e.     When a new fan drive belt has been installed, check belt tension after first 20 hours of operation. f. Wear protective overalls, and keep items of loose clothing clear of all hot and moving parts.  Use protective barrier cream when necessary. g.     Clean components and surrounding area before removing or disassembling.  All dirt and debris must be excluded from fuel injection equipment while it is being serviced. h.     Some parts are cemented with gasket compound.  Before assembly, remove all traces of old gasket and compound.  All gaskets and gasket compound must be excluded from tapped holes unless otherwise specified. i. All oil seals removed from their original position must be replaced.  Seals must be installed square in housing and all lip seals must be installed with lip facing lubricant to be retained.  Use service tool to install oil seals.  Care must be taken to prevent damaging new seal when it passes over shafts. j. Replace all nuts, bolts, capscrews, and studs with damaged threads.  Do not use tap or die to repair damaged threads which may impair the strength and/or closeness of the threads.