TM 10-4610-232-12 (a) Check air compressor oil level dipstick (1).  If oil level is below mark, add oil to top of mark. (b) Close air compressor bleed valve (27). (c) Check  AIR  COMPRESSOR  hourmeter  (2)  and  unit  log  for  last  filter  replacement.    Replacement  intervals  are shown in Table 2-14. CAUTION Clogged filters will reduce the operating efficiency of the ROWPU.  If this is the first time that the ROWPU has been started or if the ROWPU has been in storage, replace the outlet filter  before  start  up  and  after  the  air  pressure  bottle  has  been  pressurized  to  1800  psi. Thereafter, replace the outlet filter in accordance with the following table. Table 2-14.  Filter Replacement Intervals Replace every 44 hours if below 85ºF (29ºC). Outlet Filter Replace every 22 hours if above 85ºF (29ºC). Inlet Filter Replace every 250 hours. (3) If the inlet filter requires replacement: (a) Be certain COMPRESSOR OFF/ON switch (3) is OFF. (b) Unscrew filter cover (4), spring (5), and filter (6). (c) Install spring and new filter.  Reinstall filter cover. (4) If the outlet filter requires replacement: WARNING The  air  manual  blowdown  valve  must  be  bled  (opened)  before  removing  the  fitter  cap. Failure to do so will result in the cap being blown off which could cause serious injury. (a) Be certain COMPRESSOR OFF/ON switch (3) is OFF. NOTE Make certain air tank valve is closed. (b) Open outlet filter housing drain cock (7) to release air pressure.  Leave open. NOTE Do not turn vent knob on top of cap. (c) Unscrew cap (8).  Remove and throw away filter (9). (d) If oil residue appears, remove filter housing and wipe down. (e) Install new filter and reinstall cap (8). (f) Close outlet filter housing drain cock (7).  Make certain high pressure air auto blowdown block valve (10) is open. (g) Air manifold bleed valves (11) closed. (h) Air storage valve (12) open. (i) Air dryer valve (13) closed. (j) Media filter air purge block valve (14) closed. (k) Air block valves (15 thru 23 for Model WTA-060, 15 thru 22 for Model ROWPU-1) open. (I) Turn COMPRESSOR OFF/ON switch (3) ON.  Notify unit maintenance if compressor malfunctions. (4.1) Make sure air storage valve is open. (5) Make sure all vent, drain, and sample valves listed in Table 2-15 are closed. (6) Make sure manual valves are positioned as listed in Table 2-16. NOTE After air pressure has reached 85 psi (586 kPa), proceed with step 7 below. (7) Remove utility air hose (24) from storage box 2 (43, Figure 2-24) and connect utility air hose to utility air connection (25, Figure 2-34) to stabilizers (26).  Use utility air hose and fill stabilizers 26 to 30 psi (207 kPa) and use tire pressure gage to check pressure. Change 12  2-67