TM 9-2815-225-34&P 3-52. FUEL INJECTOR REPAIR (Contd) LOCATION/ITEM ACTION REMARKS b.  Cleaning(Contd) CAUTION Injector barrels and plungers are not interchangeable.  To avoid equipment damage, do not mix injector barrels and plungers. 10. Plunger (2), barrel (9), and Clean. The use of an ultrasonic cleaner is injector cup (10) recommended for plunger, barrel, and injector cup. WARNING Compressed air used for cleaning purposes will not exceed 30 psi (207 kPa).  Use only with effective  chip  guarding  and  protective  equipment  such  as  goggles  or  shield,  gloves,  etc. Failure to comply may result in injury to personnel. 11. All cleaned parts Dry with compressed air.   Place all cleaned injector assembly (1) part under cover to prevent contamination. c.  Inspection CAUTION Handle injector plunger with care to prevent damage. 12. Plunger (2) Inspect for: a.  Scuffing or scoring.   Replace plunger (2) and barrel (9) if scuffed or scored. b.  Bright spots at machined area This is a normal condition. bottom and mid-point. c.  Surface defects. Replace if evident. d.  Cracks or looseness. Replace if cracked or loose.  Rotate by hand to determine looseness. 13. Injector spring (6) Inspect for: a.  Excessive wear. b.  Spring compression.   Use suitable spring tester.  Discard if 138 lb (62.65 kg) or less at 1.663 in. (42.240 mm) spring height. c.  Spring squareness.   Use dial indicator.  Rotate spring and measure at top and bottom of spring (6).  Discard if 0.016 in. (0.406 mm) is exceeded. 14. Injector cup (10) Inspect spray holes and tip for: Use magnifying glass.  Compare to new cup. a.  Abrasive wear. Internally and externally. b.  Corrosion and erosion. If hole size has not changed, reuse. c.  Enlarged or distorted spray Discard if holes are enlarged. holes. 3-344