TM 10-3930-664-10 3-8. RADIATOR - SERVICE This task covers: Checking radiator coolant level and adding coolant as necessary. CAUTION Lowering or raising the tow bar requires two people. Tow bar   weighs   120   pounds   (54   Kg)   which   exceeds   the weight one person may safely handle. 1. LOWER THE TOW BAR (1), PARAGRAPH 2-26. WARNING Don’t  remove  the  radiator  cap  when  the  engine  is  hot; hot   steaming   gases   will   escape   and   burn   you.   Use extreme care when removing the  radiator  pressure  cap. The sudden release of pressure can cause a steam flash which could seriously injure you. Slowly loosen cap to the first  stop  to  relieve  pressure  before  removing  the  cap completely. After use, tighten cap securely. NOTE Crossmembers  of  tow  bar  shall  be  used  as  steps  for access to the radiator cap. 2. REMOVE RADIATOR CAP (2). 3. CHECK      COOLANT      LEVEL      IN   RADIATOR. COOLANT   LEVEL   MUST   BE   ONE   INCH   (2.54   CM) BELOW THE BOTTOM OF THE FILLER NECK. NOTE Use  a  50-50  mix  of  ethylene  glycol  (MIL-A-46153)  and clean water for coolant. Plain water is not recommended.    Make    coolant    mixture    before    adding coolant to the radiator. 4. ADD    COOLANT    TO    RADIATOR.    ADD    UNTIL LEVEL IS ONE INCH (2.54 CM) BELOW THE BOTTOM OF THE FILLER NECK. 5. RAISE THE TOW BAR (1), PARAGRAPH 2-26. 3-17