TM 10-3930-671-24 Engine Coolant Change It   is   recommended   to   drain   and   replace   the   engine coolant every 2000 hours, or once a year. Cooling System Capacity: 9 quarts (8.5 L). Refer to Section 2.1, Service Specifications. Draining Radiator & Cooling System WARNING The  radiator  is  very  hot  and  pressurized during   vehicle   operation.      Let   radiator cool  before  removing  cap.    Failure  to  do so can result in serious burns. NOTE The radiator does not have a drain fitting. 1. Place a large drain pan (minimum capacity 11 q [10.4 L]) under radiator and engine. 2. Remove the radiator cap. 3. Loosen    hose    clamp    and    remove    the    lower coolant  hose  from  radiator.    Drain  coolant  into drain pan. 4. Remove  coolant  drain  plug  from  engine  block. Drain coolant into drain pan. 5. Inspect  coolant  hoses  and  clamps  to  determine if they need to be replaced. Cleaning & Flushing Cooling System NOTE If  the  condition  of  the  used  coolant indicates  severe  contamination,  rust deposits, scale, or oil in the system, it may  be  necessary  to  clean  and  flush cooling system with commercial cleaner.      Choose   a   product   from   a reliable manufacturer  and  follow  the manufacturer’s   recommendations   in its use. 1. Install lower radiator hose. 2. Install coolant drain plug in engine block. 3. Fill cooling system and perform the cleaning and flushing operation in accordance with the recommended procedure. 4. Drain radiator and cooling system completely, as noted above. 5. Remove drain pan. Filling Cooling System NOTE To   cycle   coolant   from   the   recovery reservoir into the radiator, run engine until it reaches operating temperature,   then   stop   the   engine. Check   coolant   level   in   the   coolant recovery    reservoir    when    engine    is cold. With     entire     cooling     system     drained,     the     following procedure should be used to ensure complete fill: 1. Fill   radiator   to   the   bottom   of   the   filler   neck opening  with  new  coolant.    Use  recommended mixture only. 2. Install radiator cap securely. 3. Fill the coolant recovery (overflow) bottle reservoir  to  the   ’COLD’   level   line   with   coolant mixture. 4. Start and run engine until radiator upper hose is warm, indicating thermostat is open and coolant is   circulating   through   the   system.      Check   for leaks at the hose connections and engine block plug. 5. Check  coolant  level  in  recovery  reservoir  when coolant  is  cold.    Add  coolant  as  required  to  the correct fill level. F-97