TM10-3930-660-20 17-8. CAB HEATER - REPLACE This  task  covers: a. Removal b. Installation Initial Setup Tools Tool Kit, Automatic Mechanics Equipment  Condition Vehicle parked on level ground. Materials/Parts Lockwasher (8, 10) Loctite 59241 (App. C, Item 42) Starwasher  (6) Tags (App. C, Item 51) Seat removed, para. 16-13. Negative battery cable disconnected, para.  8-44. Engine coolant drained, para. 7-3. The cab heater is located inside the cab under  the  seat. Heater hoses and attaching hardware are accessed from under the cab. REMOVAL 1. REMOVE TWO CONNECTORS (1)/ TWO CONNECTOR BUSHINGS (2) AND TWO ELBOWS (3) FROM PORTS OF HEATER (4) UNDER CAB. 17-21