TM  10-3930-643-34 ENGINE,  FUEL,  EXHAUST  AND  COOLING  TROUBLESHOOTING  AND  MAINTENANCE. 4-9. Oil Cooler. (Sheet 4 of 5) TESTING 8. 9. 10. 11. 12. NOTE Plugs must be installed in oil cooler for testing. Install two new seals (6) and two pressure plates to inlet and outlet flange of oil cooler (5), refer to Appendix D, Part D-5 for fabrication of pressure plates. Using a 9/16” socket and socket wrench  handle,  install  four washers (4), bolts (2) and nuts (11). Attach air hose and immerse oil cooler (5) in water. Water should be at 120 degrees F. COMPRESSED  AIR  HAZARD Compressed air used for cleaning purposes will not exceed 30 psi. Use only with effective chip guarding and personal protective equipment  (goggles/shield,  gloves, etc.). Using an air hose, apply 15 psi pressure.  No  moving  or  growing bubbles should be visible for about one minute. If moving or growing bubbles are present after one minute, replace cooler. Remove oil cooler (5) from water and disconnect air hose. Go to sheet 5 4-71