TM 10-3930-675-20-2 0050 00-3 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: WARNING • DO NOT service cooling system unless engine has been allowed to cool down. This is a pressurized cooling system and escaping steam or hot coolant will cause serious burns. • DO NOT remove cooling system radiator cap when engine is hot. Allow engine to cool down. Failure to follow this warning may cause serious burns. 5 Quarterly (300 Hours) Engine Coolant Filter a.  Replace coolant filter (WP 0068 00). b. Inspect cooling system for leaks and damage. If authorized, replace dam- aged components. 6 Quarterly (200 Hours) Front and Rear Propeller Shafts Lubricate front and rear propeller shafts (LO 10-3930-675-12). 7 Quarterly (200 Hours) Tophandler Pinion and Ring Gear Lubricate pinion and ring gear (LO 10- 3930-675-12). 8 Semi- annual (1000 Hours) Transmission Oil Filter Remove  and  replace  transmission  oil filters and oil (WP 0115 00 and LO 10- 3930-675-12). 9 Semi- annual Transmission Vent Hose Inspect  for  plugged  hose  and  valve. Clean if necessary. 10 Semi- annual (1000 Hours) Hydraulic System Servo Filter Replace servo filter and top off hydrau- lic fluid (WP 0183 00 and LO 10-3930- 675-12). 11 Semi- annual (1000 Hours) Hydraulic System Pressure Filters Replace   pressure   filters   and   top   off hydraulic  fluid  (WP  0183  00  and  LO 10-3930-675-12).