TM 55-1520-240-T 7-2.4 UTILITY HYDRAULIC SYSTEM OPERATIONAL CHECK 7-2.4 INITIAL SETUP Electrical Power Off Applicable Configurations: Hydraulic Power Off All No. 1 and No. 2 Flight Control Systems Serviced. Tools: Flight Controls Connected and Rigged Aircraft Mechanic's Tool Kit, Control Locks and Rig Pins Removed NSN 5180-00-3234692 Visual Check of Utility Hydraulic System Performed Materials: (Task 7-2.3) None General Safety Instructions: Personnel Required: Medium Helicopter Repairer (2) Rotary Wing Aviator (2) WARNING References: TM 55-1520-240-10 Keep hands away from flight controls. TM 55-1520-240-123 Application of hydraulic power will cause flight controls to move and rotor Equipment Condition: blades to flap.  Injury to personnel can TM 55-1520-240-23: occur. Battery Connected TASK RESULT 1. Check that HYDRAULICS OIL LEVEL circuit breaker If circuit breaker (1) is open, close it.  If it opens again, go (1) is closed. to Task 7-2.5. 2.  Press and hold LEVEL CHECK switch (2).  Check Pointer on indicator (3) shall move upscale and indicate indication on UTILITY RESERVOIR LEVEL indicator level of fluid in reservoir.  If pointer does not move, go to (3). Task 7-2.6.  If pointer moves and indicates low level, service utility hydraulic system.  Refer to TM 55-1520-240- 23. 3.  Release LEVEL CHECK switch (2). 4.  Set BATT switch (4) to ON. 5.  Check UTIL HYD SYS capsule (5), NO. 1 HYD FLT Capsules (5, 18 and 19) shall be on.  If capsule (5) is not, CONTR (Without 74) HYD 1 (With 74) capsule (18) go to Task 7-2.7 or 7-2.7.1.  If capsule (18 or 19) is not on, and  NO. 2 HYD FLT CONTR (Without 74 ) HYD 2 (With go to Task 7-1.14. 74 ) capsule (19). 6. Start APU.  Refer to Task 15-1.5.  CHECK UTIL HYD UTIL HYD SYS capsule (5) shall go out.  If it is on, check SYS capsule (5). UTILITY HYDRAULICS indicator (10) and record indica- tion.  Shut down APU and go to Task 7-2.8. 7. Check that HYDRAULICS PWR XFR UTIL BLOWER, If any circuit breaker (6, 7, 8, or 9) is open, close it.  If PWR AND UTIL SYS CONT and UTIL HYD COOLING XFR circuit breaker (6) is open, close it.  If it opens again, BLOWER circuit breakers (6, 7, 8, and 9) are closed. go to Task 7-2.9.  If UTIL BLOWER circuit breaker (7) opens again, go to Task 7-2.10.  If UTIL SYS CONT circuit breaker (8) opens again, go to Task 7-3.7.  If UTIL HYD COOLING BLOWER (9) opens again, go to Task 7-2.11. TASK RESULT 8. Check UTILITY HYDRAULICS indicator (10). Indicator (10) shall indicate  3200 to 3500 psi and pointer shall not fluctuate more than 50 psi.  If indicator does not indicate 3200 to 3500 psi go to Task 7-2.8 if pointer fluctuates more than 50 psi, go to Task 8-7.3. 9. Check UTILITY PRESS and RTN FILTER lights (11 If light (11 or 12) is on, go to Task 7-2.12. and 12). 10. Check APU FAULT light (13). If light (13) is  on, go to Task 7-2.13. 11. Press and release UTILITY PRESS and RTN FILTER Lights (11, 12, 13, and 14) shall momentarily come on.  If lights (11 and 12) and APU and UT PUMP FAULT any light does not come on, go to Task 7-2.14. lights (13 and 14). 12. Set FLT CONTR switch (17) to BOTH.  Set POWER XFR NO. 1 HYD FLT CONTR and NO. 2 HYD FLT CONTR NO. 1 and POWER XFR NO. 2 switches (15 and 16) to (Without 74) HYD 1 and HYD 2 (With  74) capsules (18 ON. and 19) shall go out.  If either capsule is still on, go to Task 7-2.15. 13. Move pilot's pitch and roll control and thrust lever Control and lever (19 and 20) travel shall be smooth.  NO. (20 and 21) through their travel range. 1 and NO. 2 HYD FLT CONTR (Without 74) HYD 1 and HYD 2 (With 74 ) capsules (18 and 19) shall stay out. Pointer on UTILITY HYDRAULICS TEMPERATURE indi- cator (22), shall move upscale and not exceed 95C.  If either capsule comes on, go to Task 7-2.16.  If indicator pointer exceeds 95C, go to Task 7-2.17. 14. Have pilot start engines and establish 100% rotor rpm. Indicator (10) shall indicate  2900 to 3200 psi and shall not Stop APU.  Check UTILITY HYDRAULICS indicator fluctuate more than 50 psi.  If indicator does not indicate (10). 2900 to 3200 psi or if pointer fluctuates more than 50 psi, replace utility hydraulic pump. 15. Check UTILITY PRESS and RTN FILTER lights (11 If light (11 or 12) is on, go to Task 7-2.12. and 12). 16. Check UT PUMP FAULT light (14). If light (14) is on, go to Task 7-2.13. 17.  Remove heater compartment acoustic blanket.  Refer to TM 55-1520-240-23. 18.  Have pilot stop engines and start APU. GO TO NEXT PAGE 7-80  Change 17