TM 10-3930-675-20-2 0050 00-5 Table 1. Preventive Maintenance Checks and Services (PMCS) for the RT 240 RTCH - Continued. Item No. Interval Man- Hours Item To Check/ Service Procedure Equipment Not Ready/ Available If: 23 Semi- annual (1000 Hours) Engine Bell Housing Remove  drain  plug  from  bell  housing and  check  for  signs  of  oil  or  water.  If water  is  noted,  investigate  source  and correct.  If  oil  is  noted,  notify  Direct Support Maintenance. 24 Semi- annual Bogie Wheel Assembly Exercise   bogie   wheel   assembly   (TM 10-3960-675-10).  Inspect  and  clean  as required. 25 Semi- annual Cab Tracks and Locking Bars Place cab and boom in transport mode (TM   10-3930-675-10)   and   check   for free movement of cab rollers in tracks. Clean and inspect for damage. Replace any   damaged   component   (WP   0142 00). 26 Semi- annual Cab Drain Valves Inspect   two   drain   valves   under   cab. Press  valve  with  two  fingers  to  drain water. 27 Semi- annual Front and Rear Propeller Shafts Inspect mounting studs and locknuts for looseness and damage. 28 Semi- annual Cab Air Filters Service cab air filters (WP 0160 00). 29 Semi- annual Cab Air Conditioner Remove  plug  from  condenser  fan  box behind cab. With engine and air condi- tioner  running,  inspect  sight  gage  on top of receiver-drier for bubbles. If bub- bles  are  present,  notify  Direct  Support Maintenance to charge air conditioning system. 30 Annual Hydraulic System AOAP Oil Sampling Valve a.  Ensure hydraulic system is at operat- ing temperature. b.  Remove   cap   from   discharge   port. Clean sampling valve port with rag. c.  Open and close knob of valve suffi- ciently  to  allow  approximately  2  oz (60  ml)  of  oil  to  be  collected  into suitable container. Discard oil. d.  Open   and   close   knob   of   valve   to allow   sample   to   be   collected   into clean sample bottle approximately 1/2 in (1.3 cm) below neck of sample bot- tle.