TM 10-3930-671-24 Compressed  air  used  for  cleaning  purposes  must  not exceed   regulated   30   psi   (207   kPa).   Use   only   with effective chip guarding and personal protective equipment (goggles/ shield, gloves, etc.) to prevent injury to personnel. b. Inspect   the   radiator   for   damage   and   clogging from dirt contamination. Air clean the radiator if it has not already been cleaned as part of the PM procedure.  Air  pressure  should  not  exceed  30 psi (207 kPa). c. Check  to  be  sure  that  the  fan  blades  are  not loose  or  damaged  and  that  the  fan  is  installed correctly (Fan installed backwards is  a  common problem). d. Check  the  fan  drive  belt  for  proper  tension  and adjust,  as  necessary.  If  tension  is  low,  the  belt will  slip.  If  belt  tension  is  too  high,  the  bearings and  seals  in  the  water  pump  and  alternator  can be damaged. e. Check the exhaust pipe to be sure that  exhaust is not blowing into radiator. f. As a final step, if necessary: 1) Pressure test the cooling system. 2) Pressure test the radiator cap. 3) Check the thermostat. 4) Check   the   coolant   for   freeze   protection level. 5) Check overflow reservoir and hoses. 6. TMD27 [2.7L] Diesel Engine a. Check  glow  plugs  and  inspect  glow  plug  wiring. Repair or replace, as needed. b. Inspect  fuel  lines  for  leaks.  Adjust  fuel  control linkage and accelerator pedal linkage to allow for full   travel   of   arm   on   fuel   injection   pump,   as necessary. Refer  to  Section  5.3,  Diesel  Fuel  System,  for  additional information. 7. Re-check Engine Performance a. Remove   the   tachometer,   vacuum   gauge,   and timing light. b. Stall   Test.   Run   a   stall   test   to   check   engine performance after tune-up. Tune-Up Completion When you have systematically completed these tune-up procedures,     you     should     have     been     successful     in restoring the engine to its peak level of performance,  or otherwise determined the need for additional maintenance or repair of the engine. a. Lower  and  latch  the  seat  deck.  Be   sure   seat deck  is  correctly  latched.  Install  and  close  the side  doors.    Lower  the  drive  wheels  to  the  floor and remove any blocking, if used. b. Test drive the truck. c. Clean  up  any  loose  dirt  and  spills.  Wipe  off  the truck. F-77 (F-78 blank)