TM 5-6115-593-12 TO 35C2-3-463-1 TABLE 4-2.  ORGANIZATIONAL PREVENTIVE MAINTENANCE CHECKS AND SERVICES. NOTE: Within designated interval, these checks are to be performed in the order listed. W-WEEKLY (40 HRS)   M-MONTHLY (100 HRS) S-SEMIANNUALLY (500 HRS) W M S o Drain and refill sump 9 o Ether Kit Check ether tank for fullness Shake to determine contents: if empty then replace tank. Ref.  par. 4-65. 10 Engine Assembly Ref. Section XXVI. o Inspect water pump belt for wear and proper adjustment. Ref. par. 4-67. o Inspect engine for loose connections, leaks in oil, fuel, and water system. o Change fuel filters. Ref. par. 4-53 and 4-75. 11 o Clean crankcase breather Ref.  par. 4-8a (5). o Check valve tappet clearance and reset, if necessary. Ref. par. 4-87 b. o Inspect oil pressure switch, (par. 4-73), lube oil cooler (par. 4-76), injectors (par. 4-78) for signs of damage. o Inspect temperature switch (par. 4-82), vibration damp- er (par. 4-83), intercooler (par. 4-84), exhaust manifold (par. 4-85), and water mani- fold (par. 4-86) for signs of damage. o Inspect rocker arm shaft and rocker arm assemblies for evidence of misalignment or damage. Ref. par. 4-87. o Check oil filter pressure differential.  Pressure drop from inlet to outlet should not exceed pressure logged after latest installation of spin-on oil filters by more than 10 psi (0.7 kg/cm² ) with 140°F (60C) oil temperature o Service water filter. Ref. par.-4-68. INTERVAL ITEM NO. ITEM TO BE INSPECTED Equipment is Not Ready/Available If: PROCEDURES CHECK FOR AND HAVE REPAIRED OR ADJUSTED AS NECESSARY 4-19