TM 5-3895-370-14&P Table 4-2.  Unit Preventive Maintenance Checks and Services Mo - Months Hr - Hours Item Interval Item to Be No. Mo Hr Inspected Procedure ENGINE 1 3 250 Engine Crank- Inspect front and rear oil seals for leakage.  Change the lube oil and case and Oil filter (para 4-24 and 4-31).  Refer to Chapter 3, Section I for Seals Lubrication Instructions. 2 6 500 Fuel Filters Change fuel filters (para 4-44).  Bleed fuel system if required (para 4-42). 3 12 1000 Valves Inspect valve covers and seals for damage and leakage. Adjust valve lash clearance (para 4-25): Intake - 0.010 in.  (0.254 mm) Exhaust - 0.020 in.  (0.508 mm) 4 6 500 Radiator Check the anti-freeze concentration.  Add enough anti-freeze to Assembly protect the engine to -24 degrees F (-31 degrees C) (para 3-8). 5 12 1000 Cooling System Drain the cooling system (para 4-56).  Check for damaged hoses and loose or damaged hose clamps.  Replace as required (para 4-57). Check radiator for leaks, damage, and build-up of dirt.  Clean and repair as required (para 4-53).  Flush the system until the water is clean.  Use a mixture of 50% water and 50% anti-freeze.  System capacity is 6 gal. (23 l). 6 12 1000 Drive Belt, Check the belt deflection at the longest span of belt.  Maximum Tensioner deflection is 3/8 to 1/2 in. (9.5 - 12.7 mm).  Replace belt if required Bearing, and (para 4-61).  Check the tensioner and fan hub bearings.  Should spin Fan Hub freely with no rough spots, wobble, or end play.  Replace  tensioner or fan hub if required (paras 4-62 and 4-60). WARNING If   NBC   exposure   is   suspected,   all   air   filter   media should  be  handled  by  personnel  wearing  protective equipment.    Consult  your  unit  NBC  Officer  or  NBC NCO for appropriate handling or disposal procedures. 7 3 250 Air Cleaner/ Remove and inspect outer and inner air cleaner elements Intake System (para 4-37).  Tighten or replace parts as necessary to make sure air intake system does not leak (i.e. cracked hoses, loose clamps, punctures, etc.).  Replace elements as necessary. 4-10