TM 5-4320-215-12 b.    The  preventive  maintenance  services  to  be performed at quarterly intervals are listed and described in  paragraph  33.    The  number  opposite  each  service refers to a corresponding number on DA Form 464 and indicates  the  services  to  be  performed.    The  number listed under "inspection" indicates the minimum inspection requirements for the equipment. 33.  Quarterly Preventive Maintenance Service Inspection Service Quarterly GENERAL 1 1 Before-operation services.  Perform the before operation services listed in paragraph 31. 2 2 Lubrication.  Inspect the entire pumping unit for damaged oil lines, leak- ing oil seals, and indications of insufficient lubrication. 2 Lubricate in accordance with the current lubrication order.  Replace dam- aged lines or fitting.  Correct or report all deficiencies to field man- tenance. 3 3 Tools and equipment.  Inspect the condition of all tools and equipment assigned to the unit. 3 Make sure they are clean and properly stowed or mounted. 4 4 Fire extinguisher.  Inspect the bromochloromethane type fire extinguish er for insufficient charge, judging by sound and weight.  Do not discharge contents.- Inspect for excessive corrosion and insecure mounting. 4 Correct all deficiencies or report them to field maintenance.  Refer to field maintenance for refilling and maintenance.  Weigh a monobromo- tribluoromethane type fire extinguisher every six months and replace the cylinder if the gross weight has decreased four ounces or 'on Lubricate the cylinder neck threads with one drop of OE  30 oil before reassembly. 5 5 Publications.  See that a copy of this manual, TM 5-280 -20912, the current lubrication order, and DA Form 285 are on or with the equip- mnent and in serviceable condition. 6 6 Appearance.  Inspect the general appearance of the pumping unit, pay- ing special attention to uncleanliness, illegibility of identification mark- ings, and poor condition of paint. 6 See that all deficiencies noted are corrected' or reported to field tenance. 7 7 Modifications.  See that all available modification work orders applying to this pump unit have been complied with and recorded on DA Form 478, DA Form 5-73, and DA Form 5-73a, as applicable. ENGINE 11 11 Cylinder head, manifolds, mufflers, and exhaust pipe.  Inspect the in- take and exhaust manifolds for crack, breaks, lose mounting, and evidence of leakage.  Inspect the muffler and exhaust pipe for loose mounting, leaks, and excessive rust. 11 Tighten all mounting hardware.  Replace a defective intake or exhaust manifold, gaskets, muffler, and exhaust pipe (TM 5-280209-12) 12 12 Valve mechanism.  Inspect the valve cover and gasket for signs of dam- age.  Inspect the valve mechanism for defective part.  Make r that the valve mechanism is receiving sufficient lubrication. 12 Replace a defective valve cover or gasket (TM 5-2805-209-12).  Report defective valves or insufficient lubrication to field maintenance. 13 13 Compression test.  Refer to TM  5-2805-2o09-12 and test the compres- sion of each cylinder. 26