7–10. PRIMARY HYDRAULIC SYSTEM – MAINTENANCE OPERATIONAL CHECK (cont)

TM 1-1520-238-T-5 7–56 Change 5 7–10. PRIMARY HYDRAULIC SYSTEM – MAINTENANCE OPERATIONAL CHECK (cont) 7–10 NOTE If referenced out of one paragraph or volume into another for additional troubleshooting, upon completion of the task, return to the maintenance operational check for the original paragraph or volume. 1. Perform visual check of primary hydraulic system with AGPU operating (TM 1-1520-238-PMS). Replace any leaking component (TM 1-1520-238-23). a. If hydraulic fluid is leaking from drilled passageway/port on inboard side of primary hydraulic manifold about one inch below dirty filter indicators, replace indicator packings (TM 1-1520-238-23). 2. If rotors begin to turn when primary hydraulic external power is applied, replace primary hydraulic pump outlet check valve (TM 1-1520-238-23). 3. Remove external pressurized air and hydraulic (primary) power (TM 1-1520-238-23). 4. Do not close access doors or install access panels until maintenance operational check is completed. WARNING The hydraulic system is pressurized to 3000 psi. Be certain that trapped hydraulic pressure is released before loosening any connections. Failure to do so could result in death or serious injury. If injury occurs, get medical aid immediately. NOTE Total primary system fluid volume is 0.75 gallons. 5. Drain primary reservoir to REFILL level if required (TM 1-1520-238-23). NOTE Decal on access door R325 shows proper positioning of selector valve of hydraulic hand pump. 6. Set hydraulic hand pump selector valve (fig. 7–21) to INBOARD position. SELECTOR VALVE INBOARD POSITION HAND PUMP HANDLE AFT POSITION OUTBOARD POSITION M68-006 Figure 7–21. Hydraulic Hand Pump Selector Valve