TM 10-3930-659-20 16-15.    HEATER VENTILATORS AND DUCT HOSES REPLACEMENT (Con't). 9. Remove   four   screws   (23),   washers   (24),   two brackets  (22),  ventilator  (20),  two  rubber  strips (21),    and    louver    housing    (17)    from    heater housing (15). b. INSTALLATION 1. Install louver housing (17), two rubber strips (21), ventilator (20), and two brackets (22) on heater housing (15) with four washers (24) and screws (23). 2. Install three isolators (11), right duct (12), and left duct (16) on heater housing (15) with four washers (14) and screws (13). 3. Position two hose clamps (18) on duct hose (19). 4. Install duct hose (19) on louver housing (17) and right duct (12), and tighten two hose clamps (18). TA707013 16-53