TM10-3930-660-20 7-3. RADIATOR    SERVICE/TEST    (Cont’d) CHECKING AND ADDING ENGINE COOLANT 1. CHECK COOLANT LEVEL IN THE OVERFLOW TANK  (1). TANK (1) SHOULD BE 1/3 TO 2/3 FULL. NOTE A 50-50 mixture of ethylene glycol and clean water is used in the 6000M. Use of plain water coolant is not recommended. Never add coolant without first diluting to a 50-50 mixture. 2. 3. IF OVERFLOW TANK (1) IS BETWEEN 1/3 FULL AND EMPTY, OPEN OVERFLOW TANK CAP (3) AND ADD ONE QUART OF cOOLANT  . CLOSE CAP (3). IF OVERFLOW TANK (1) IS COMPLETELY EMPTY. OPEN OVERFLOW TANK CAP (3) AND ADD TWO QUARTS OF COOLANT. CLOSE CAP (3). SLOWLY REMOVE RADIATOR CAP (4) AND ALLOW PRESSURE TO ESCAPE. ADD COOLANT TO RADIATOR (2), AS NECESSARY, UNTIL COOLANT LEVEL REACHES BOTTOM OF FILLER  NECK. INSTALL RADIATOR CAP (4). 7-3