TM-9-2320-361-24-2 Field Maintenance Manual Volume 2 for M44A2 Series Trucks
Page 838 of 1144
TM 9-2320-361-24-2 0422 00 0422 00-2 ENGINE COOLANT HEATER OVERHEAT SWITCH AND IGNITER MAINTENANCE (Contd) NOTE Prior to removal, tag all lead wires for installation. OVERHEAT SWITCH REMOVAL 1. Remove four screws (6) and guard (7) from heater housing (8). 2. Remove nut-assembled lockwasher (2), ground lead (3), air tube (4), and elbows (1) and (5) from heater housing (8). Discard nut-assembled lockwasher (2). 3. Disconnect lead (9) from overheat switch (13). 4. Disconnect leads (10) and (12) from tab connector (11) and tab connector (11) from overheat switch (13). 5. Remove nut (33), lockwasher (32), retainer (31), overheat switch (13), washer (14), and O-ring (15) from heater housing (8). Discard lockwasher (32) and O-ring (15). IGNITER REMOVAL 1. Remove four nut-assembled lockwashers (27) and end plate (26) from heater housing (8). Discard lockwasher (27). 2. Remove screw-assembled lockwasher (21), ground strap (22), igniter lead (23), and lockwasher (24) from burner (16). Discard screw-assembled lockwasher (21) and lockwasher (24). 3. Remove nut (28), ground strap (22), and lockwasher (29) from stud (30). Discard lockwasher (29). 4. Remove nuts (19) and (18), preheater resistor strap (17), igniter (20), and gasket (25) from burner (16). Discard igniter (20) and gasket (25). INSPECTION Test overheat switch (13) for continuity. If continuity does not exist, replace overheat switch (13). IGNITER INSTALLATION CAUTION Igniter is fragile. Use care when installing igniter. Failure to do so may result in damage to equipment. 1. Install new gasket (25) and new igniter (20) on burner (16). 2. Place preheater resistor strap (17) on igniter (20) and install with two nuts (18) and (19). 3. Install ground strap (22) on stud (30) with nut (28) and new lockwasher (29). 4. Install ground strap (22) and igniter lead (23) on burner (16) with new lockwasher (24) and new screw-assembled lockwasher (21). 5. Install end plate (26) on heater housing (8) with four new nut-assembled lockwashers (27). OVERHEAT SWITCH INSTALLATION 1. Install new O-ring (15), washer (14), overheat switch (13), and retainer (31) on heater housing (8) with new lockwasher (32) and nut (33). 2. Install leads (10) and (12) on tab connector (11) and install tab connector (11) on overheat switch (13). 3. Install lead (9) on overheat switch (13). 4. Install air tube (4), elbows (1) and (5), and ground lead (3) on heater housing (8) with new nut- assembled lockwasher (2).