TM 1-1500-204-23-3 an  outlet  spacer  will  be  at  both  ends.    Also,  make  sure  each  screen  is  located  between  an  outlet  spacer  and  an  inlet spacer. 2 Install the outer end plate on the screen and spacer buildup; then install the cover on the end plate. 3 Place a new seal on the cover plug and install the plug in the threaded end of the baffle. The plug must be tightened to the torque prescribed in the manufacturer's instructions so that the spacers and screens cannot be rotated by hand. 4 Secure  the  cover  plug  with  lockwire.    Then  remove  the  filter  assembly  from  the  holding fixture. d. Oil Screens.  Oil screens, as shown in figure 3-9, accumulate the sludge during engine operation.  These screens must be removed, inspected, cleaned, and reinstalled at regular intervals according to applicable maintenance manuals. General maintenance procedures are covered in the following paragraphs. (1) Removal.  Remove and discard the safety devices and loosen the oil screen housing or cover plate.  Be sure to use a suitable clean container to collect the oil that will drain from the filter housing. NOTE The container must be clean so that the oil collected can be examined for foreign particles. Any contamination already present will give a false indication of engine condition. (2) Inspection.  Inspect    screens    for contamination and for the presence of metal particles.  Metal particles may indicate internal engine failure. WARNING Drycleaning solvent is flammable and solvent vapors are toxic.  Use P-D-680, Type II Solvent in a well-ventilated area.  Keep away from open flames.  Avoid prolonged solvent contact with skin. When using air pressure, be extremely careful.  Do not blow stream of air toward yourself or any other person.  Users of air pressure and personnel within the immediate area shall wear safety  glasses,  goggles,  or  face  shield.    Ear  protection  may  be  required.    Pressure  will  not exceed 30 psig.  Failure to comply may result in injury. (3) Cleaning.    Clean  oil  screens  by  immersing  in  drycleaning  solvent,  Federal  Specification  P-D-680,  and washing with a soft bristled brush.  Do not use a hard-edged or pointed tool to scrape or pick at screen.  Using a light air blast,   blow   out   residual   dirt   and   fluid.      When   heavy   carbon   deposits   adhere   to   screen,   immerse   screen   in trichloroethylene, Federal Specification 0-T-634, at room temperature.  Dry with a light air blast. (4) Installation.  Reinstall the filter using new O-rings and gaskets.  Tighten housing or cover retaining nuts to the torque value specified in the applicable maintenance manual and safety as required. e. Oil Tanks.  Oil tank description and general maintenance procedures are explained in the following paragraphs. (1) Description.  Oil tanks are generally constructed of an aluminum alloy.  The tank is usually placed close to the engine and high enough above the oil pump inlet to ensure gravity feed.  The tank filler neck is positioned to provide sufficient  room  for  oil  expansion  and  for  foam  to  collect.    Some  oil  tanks  have  a  built-in  hopper,  or  temperature accelerating well, that extends from the oil return fitting on top of the oil tank to the outlet fitting in the sump in the bottom of the tank. (2) Maintenance.  General inspection and repair procedures are explained in the following paragraphs. (a) Inspection.    Inspect  the  condition  of  attaching  straps  or  other  devices  used  to  secure  the  tank  in place, the condition of the seams and walls, signs of leakage, and the security of the attached plumbing. 3-11