TM  55-1510-221-10 operating   characteristics   may   change   in   that   lower operating   temperature,   slower   acceleration,   lower engine  speed,  easier  starting,  and  shorter  range  may be   experienced.   The   reverse   is   true   when   changing from  F-40  (JP-4)  fuel  to  F-44  (JP-5)  or  Commercial ASTM   Type   A-l   fuels.   Most   commercial   turbine engines  will  operate  satisfactorily  on  either  kerosene or  JP-4  type  fuel.  The  difference  in  specific  gravity may  possibly  require  fuel  control  adjustments;  if  so, the  recommendations  of  the  manufacturers  of  the engine  and  airframe  are  to  be  followed. 2-95.  SERVICING  OIL  SYSTEM An  integral  oil  tank  occupies  the  cavity  formed between  the  accessory  gearbox  housing  and  the  com- pressor  inlet  case  on  the  engine.  The  tank  has  a  cali- brated  oil  dipstick  and  an  oil  drain  plug.  Avoid  spill- ing oil. Any oil spilled must be removed immediately.  Use  a  cloth  moistened  in  solvent  to remove  oil.  Overfilling  may  cause  a  discharge  of  oil through  the  accessory  gearbox  breather  until  a  satis- factory  level  is  reached.  Service  oil  system  as  fol- lows: 1. Open  the  access  door  on  the  upper  cowling to  gain  access  to  the  oil  filler  cap  and  dip- stick. A  cold  oil  check  is  unreliable.  If  possible, check  oil  within  10  minutes  after  engine shutdown.   If   over   10   minutes   have elapsed,  motor  the  engine  (starter  only) for   15-20   seconds,   then   recheck.   If   over 10   hours   have   elapsed,   start   the   engine and  run  for  2  minutes,  then  recheck.  Add oil  as  required.  Do  not  overfill. 2. Remove  oil  filler  cap. 3. Insert  a  clean  funnel,  with  a  screen  incorpo- rated,  into  the  filler  neck. 4. Replenish  with  oil  to  within  1  quart  below MAX  mark  or  the  MAX  COLD  on  dipstick (cold  engine).  Fill  to  MAX  or  MAX  HOT (hot  engine). 5. Check  oil  filler  cap  for  damaged  preformed packing,  general  condition  and  locking. Insure  that  oil  filler  cap  is  correctly installed  and  securely  locked  to  prevent loss  of  oil  and  possible  engine  failure. 2-82 6. If oil level is over 2 quarts low, motor or run engine  as  required,  and  service  as  necessary. 7. Install  and  secure  oil  tiller  cap. 8. Check  for  any  oil  leaks. 2-96.  SERVICING  HYDRAULIC  BRAKE  SYSTEM RESERVOIR. 1. Gain  access  to  brake  hydraulic  system  reser- voir. 2.  Remove  brake  reservoir  cap  and  till  reser- voir  to  washer  on  dipstick  with  hydraulic fluid. 3. Install  brake  reservoir  cap. 2-97.   INFLATING   TIRES. Inflate  tires  as  follows: 1. Inflate  nose  wheel  tires  to  a  pressure between  55  and  60  PSI. 2.  Inflate  main  wheel  tires  to  a  pressure between  73  and  77  PSI. 2-98. SERVICING THE CHEMICAL TOILET. The  toilet  should  be  serviced  during  routine ground  maintenance  of  the  aircraft  following  any usage. The  waste  storage  container  should  be removed,   emptied, its   disposable   plastic   liner replaced,  and  the  container  replaced  in  the  toilet cabinet.  Toilet  paper,  waste  container  plastic  liners, and  dry  chemical  deodorant  packets  should  also  be resupplied  within  the  toilet  cabinet  as  needed. 2-99. SERVICING  THE  AIR  CONDITIONING  SYS- TEM. Servicing  the  air  conditioning  system  consists  of checking   and   maintaining   the   correct   refrigerant level,   compressor   oil   level,   belt   tension   and   condi- tion,  system  leak  detection,  and  replacement  of  the evaporator  air  filters.  It  is  imperative  that  the  main- tenance  of  the  air  conditioning  system,  except  for  fil- ter   replacement,   be   accomplished   only   by   qualified refrigerant  system  technicians.  Flexible  fiberglass  fil- ters  cover  the  evaporator  coils  and  should  be replaced  after  300  hours  of  operation.  Install  filters as follows: a. Forward Evaporator Filter Replacement: 1. Remove  the  access  door  in  the  nose wheel  well  keel  under  the  refrigerant plumbing.