(4) Remove cylinder tail piece (5) and o-ring (6) from cylinder (7). b. Cleaning.      Thoroughly   clean   the   inside   of   the filter  cylinder.    Use  a  lint-free  cloth  and  hot  water  and detergent   solution   per   Federal   Specification   P-D-220. Allow cylinder to air dry. c. Inspection.        Refer    to    paragraph    6-3.b.        for general inspection. d. Repair and Replacement. (1) Minor  nicks,  scoring  or  scratches  on  shaft may   be   smoothed   with   crocus   cloth,   per Federal Specification P-C458. (2) Replace all parts that are worn or damaged to   an   extent   that   will   impair   their   normal function. e. Assembly.    To  assemble  the  mechanical  filter assembly, proceed as follows: (1) If the cylinder tail piece (5) was disassembled,    place    new    o-ring    (6)    in position and assemble tail piece (5) securely in cylinder (7). (2) Assemble  o-ring  (4)  in  position  on  element and  head  (3)  and  install  the  subassembly (3) in cylinder (7).  Tighten securely. (3) Attach  brackets  (2,  1)  to  cylinder  (7)  until ready for next higher assembly. 6-7. Air  Purification/Dehydrator  Cylinder  Assemblies. (See Figure 8-4.) a. Disassembly. To disassemble the air purification/dehydrator cylinder, proceed as follows: (1) Unscrew    and    remove    cylinder    cap    and upper   head   subassembly   (3   through   14) from cylinder (19) and cartridge (15). (2) Remove  screws  (4),  gaskets  (5)  and  dust cover (3) from cap (7). (3) Remove   retaining   ring   (6)   and   separate upper  head  (9)  from  cap  (7).    Remove  o- ring (8) from cap (7). (4) While holding the upper head (9) and head spring   (14),   remove   retaining   screw   (10) and    disassemble    upper    perforator    (11), lower   head   (12).      head   spring   (14)   and remove o-ring (13). NOTE Perform     step     (5)     only     when     necessary     to disassemble lower perforator (17). (5) Remove retainer screw (16), lower perforator    (17),    and        spacer    (18)    from cylinder (19). b. Cleaning.  Refer to paragraph 6-3.a.  for general cleaning instructions. (1) Flush the cylinder clean with P-D-680, Type II, or equivalent. (2) Clean   the   upper   head   with   the   flushing agent. (3) Allow the cylinder, head and parts to air dry until odor of the flushing agent disappears. c. Inspection.        Refer    to    paragraph    6-3.b.        for general inspection procedures. (1) Perforator    blades    (11    and    17)    for    any bending or dullness. (2) Spring (14) for breaks or set, d. Repair  or  Replacement.    Refer  to  paragraph  6- 3.c. for general repair or replacement procedures. (1) Replace     a     damaged     cap     or     cylinder. Damaged threads may cause leakage. (2) Replace damaged or dull perforators. Defective     perforators     will     not     puncture cartridge. (3) Replace a defective spring. (4) Replace all parts that are worn or damaged to   an   extent   that   will   impair   their   normal function. e. Assembly. To assemble the air purification/dehydrator   cylinder   assembly,    proceed    as follows: (1) Assemble spacer (18) and lower perforator (17)  in  bottom  of  cylinder  (19)  with  screw (16) tightened securely. (2) To assemble upper head assembly place o- ring   (13)   in   position   on   lower   head   (12). Place  o-ring  (8)  in  position  on  upper  head (9).    Assemble  spring  (14)  and  lower  head (I 2).  Assembly spring (14) and lower head (12)on    upper    head    (9),    position    upper perforator (11) and secure with screw (10). 6-7