(h) Open pressure regulator until gauge indicates  2,200  +  100  psi  (15,158  ±  690 KPa). (i) Close shut-off valve number one. (j) Open  shut-off  valve  number  two  to  relieve the outlet pressure. (k) Reconnect leakage apparatus. NOTE The priority valve assembly  should  reseal  when air   escape   ceases.      Reseal   pressure   will   be indicated  on  pressure  gauge  number  one  and should not be less than 200 psig (1,380 KPa). (I) Cycle  the  priority  valve  assembly  through test   procedures   specified   in   steps   (a) through (j) and check for leakage. (m)   Cycle  the  priority  valve  assembly  through test    procedures    specified    in    steps    (a) through (e) and check for leakage. (n) If    priority    valve    is    defective,    refer    to PRIORITY VALVE ASSEMBLY (Section V) and repair valve. d. Repair    or    Replacement.          This     paragraph contains   information   necessary   to   repair   and   replace worn or defective parts prior to assembly. (1)Minor nicks, scoring or scratches on non-critical surfaces may be smoothed with crocus cloth per Federal Specification P-C458. (2)Replace all o-rings removed during disassembly. (3)Replace all threaded parts having worn, stripped or damaged parts. (4)Replace    identification    markings    or    plates    if markings are illegible. c. Assembly. To assemble the air purification/dehydrator group, proceed as follows (see Figure 8-2): NOTE Assure  that  o-rings  (32)  are  in  place  in the ten-micron filter before adaptors (31) are installed. (1) Assemble  elbows  (17)  to  cylinder  (19,  22, 23,  24  and  25).    Screw  in  nipple  (21)  in priority valve (20) and assemble to cylinder (22).  Screw in adapter (27) into ten-micron filter (19) and attach to cylinder (25). (2) Assemble nipple (15), check valve (14), tee (13),  and  elbows  (17,  16)  on  mechanical filter (18). (3) Position    mounting    brackets    and    attach mechanical  filter  (18)  and  cylinder  (19,  22, 23, 24 and 25) using screws (12), washers (11) and nuts (10) to control panel. NOTE Elbows should be positioned as shown in Figure 8-2 on the mechanical filter and cylinders. NOTE Do   not   completely   tighten   screws   (12)   and nuts(10)    until    tube    assemblies    have    been installed. (4) Assemble  tube  assemblies  (4,  5,  6,  7  and 8) to cylinders. (5) Install tube assembly (9) at elbow (26), tube assembly (3) at elbow (17), tube assembly (2) at elbow (16) and tube assembly (1) at tee (15). 6-6. Mechanical   Filter   Assembly   (See   Figure   8-3). The following paragraphs contain disassembly, cleaning, inspection,     repair     or     replacement     and     assembly instructions for the mechanical filter assembly. a. Disassembly.  Disassemble the mechanical filter assembly only to the  extent  necessary  to  repair  or replace a defective part or parts. (1) Remove  tee  (13,  Figure  8-2),  check  valve (14),  nipple  (15)  and  elbows  (16,  17)  from filter (18).  Reassemble as required. (2) Unscrew   and   remove   filter   element   and head  (3)  subassembly  from  cylinder  head (7). (3) Remove o-ring (4) from cylinder (7). NOTE Perform    step    (4)    only    when    o-ring    (6)    is damaged and replacement is necessary. 6-6