SERVICE MANUAL REBUILDING AD-1 END COVER ASSEMBLY To   remove   the   end   cover   assembly   from   the   air dryer,   follow   Steps   1   through   6   under   "Removal   of Desiccant Cartridge AD-1 & AD-2." Before rebuilding the end  cover,  clean  the  exterior  thoroughly  using  a  quality commercial solvent. Disassembly 1. Remove  and  discard  the  large  O-rings  around the end cover. 2. Remove the exhaust elbow and clamp. 3. Remove the cap nut and discard the cap nut O- ring. 4. Place the handle of a large screwdriver in a vise and secure it. 5. Place  the  slot  in  the  plunger  (cap  nut  end)  over the blade of the screwdriver, hold it securely and remove  the  nut  from  the  plunger  using  a  1/2" socket wrench. 6. Remove  the  plunger,  spring  and  valve;  discard the valve. 7. Clean   and   inspect   the   plunger   bore   and   the valve seat. 8. Remove and  discard  the  three  O-rings  from  the plunger, clean the plunger. If     during     the     serviceability     checks it was determined that the heater and thermostat were defective, replace end cover as an assembly. Reassembly 1. Using   Item   1   of   LUBRICATION   SPECIFICA- TIONS,    lubricate    and    install    O-rings    on    the plunger and cap nut. 2. Lubricate the plunger bore and install the spring and plunger (through the cap nut end). 3. Install  the  valve  on  the  plunger  making  certain the chamfered end of the valve is in contact with the metal seat of the body. 4. Using    the    screwdriver    held    in    the    vise,    as described    in    Steps    4    and    5,    compress    the plunger     into     the     bore     while     installing     and tightening the nut. 5. Install the cap nut and tighten it. 6. Lubricate  and  install  the  large  diameter  O-ring around  the  end  cover  assembly  with  Item  1  of LUBRICANT SPECIFICATIONS. REBUILDING AD-2 END COVER ASSEMBLY To   remove   the   end   cover   assembly   from   the   air dryer,   follow   Steps   1   through   6   under   "Removal   of Desiccant Cartridge AD-1 & AD-2." Before rebuilding the end  cover,  clean  the  exterior  thoroughly  using  a  quality commercial solvent. Disassembly 1. Remove and discard the large O-ring around the end cover assembly. Fig. 17 AD-2 End Cover Assembly 2. Remove   the   single   6-32   screw   securing   the exhaust diaphragm and separate the diaphragm, washer and screw. Discard the diaphragm. 3. Remove the three No. 6-32 screws securing the exhaust cover and remove the exhaust cover. 4. Remove the purge valve assembly, the large hex cap nut from the end cover and discard both O- rings around the cap nut. 5. Using    a    7/16"    socket    wrench    and    a    large screwdriver,  remove  the  1/4"-20  hex  head  cap screw which holds the assembly together. 6. Separate   capscrew,   purge   valve,   purge   valve piston and the piston return spring. 7. Discard  the  piston  O-ring,  the  purge  valve  and the piston return spring. CTS-4079 - CHAPTER XIV - Page 10