TM 10-3930-659-20 17-31.    HYDRAULIC OIL RETURN FILTER ASSEMBLY REPLACEMENT (Con't). 6 Remove  adapter  (10)  and  preformed  packing  (11)  from  hydraulic  oil  return  filter  head  (2).   Discard  preformed packing. CAUTION Use care not to damage hydraulic oil filter restriction switch when removing bolts. 7. Remove four bolts (5), washers (4), and hydraulic oil return filter head (2) from hydraulic reservoir (3). 8. Lower  hydraulic  oil  return  filter  head  (2)  from  hydraulic  reservoir  (3)  and  remove  hydraulic  oil  filter  restriction switch (see paragraph 6-35). c. FILTER HEAD INSTALLATION 1. Install hydraulic oil filter restriction switch (see paragraph 6-35). 2. Install hydraulic oil return filter head (2) on hydraulic reservoir (3) with four washers (4) and bolts (5). 3. Install new preformed packing (11) and adapter (10) on hydraulic oil return filter head (2). 4. Install  new  preformed  packing  (6)  and  adapter (7) on hydraulic oil return filter head (2). 5. Install  new  preformed  packing  (8)  and  hose  (9) on adapter (7). 6. Install new preformed packing (12) and adapter (13) on hydraulic oil return filter head (2). 7. Install  new  preformed  packing  (14)  and  hose (15) on adapter (13). 8. Fill  hydraulic  oil  return  filter  element  (1)  with clean   hydraulic   fluid   and   install   hydraulic   oil return filter element on hydraulic oil return filter head (2). FOLLOW-ON TASKS: • Check hydraulic fluid level and fill as necessary (see TM 10-3930-659-10). • Close  left  engine  upper  sideshield  (see  TM  10- 3930-659-10). TA707678 17-95