TM 1-1520-238-T-4
6130
Change 1
659.
OIL PSI NOSE GRBX 2 INDICATOR IS LIGHTED WHEN HOD DISPLAYS NORMAL
659
NGB 2 OIL PRESSURE
Tools:
Nomenclature
Part Number
Tool Kit, Aircraft
SC518099CLA01
Mechanics
Tool Kit, Electrical
SC518099CLA06
Repairers
Adapter, Straight Pipe
A1100-4-4
to Tube, Female
Pipe End, 37 Flared
Gage Pressure, Dial
GGG76
Indicating
(0-200 PSI)
Multimeter, Digital
AN/PSM-45
Personnel Required:
67R
Attack Helicopter Repairer
68X
Armament/Electrical Systems Repairer
152FG
Maintenance Test Pilot
References:
TM 1-1520-238-T-6
TM 1-1520-238-23
TM 1-1520-238-CL
TM 9-1230-476-20-2
WARNING
Turn off power before detaching or
attaching wires and connectors. High
current 28 VDC or 115 VAC is present.
Failure to do so could result in death or
serious injury.
1. Check HOD display NGB 2 oil temperature
reading.
Is reading 140 C or higher?
YES
Go to step 3.
NO
Go to step 2.
2. Detach P18. Check OIL PSI NOSE GRBX 2
indicator.
Does indicator remain lighted?
YES
Refer to TM 1-1520-238-T-6 to
troubleshoot the pilot
caution/warning system.
NO
Go to step 4.
3. Visually inspect NGB 2 for low oil level and
damage (TM 1-1520-238-23).
Is damage present?
YES
Replace NGB 2
(TM 1-1520-238-23).
NO
Go to step 6.
4. Check for short between P60D and P60E.
Does short exist?
YES
Replace NGB 2 low oil pressure
switch (TM 1-1520-238-23).
NO
Go to step 5.
5. Detach P18 and check for short between J60D
and ground.
Does short exist?
YES
Repair shorted wire between
J60D and P1845.
Go to paragraph 613.
NO
Refer to TM 1-1520-238-T-6 to
troubleshoot the pilot
caution/warning system.
6. Remove NGB 2 oil pressure transducer
(TM 1-1520-238-23). Install pressure gage. Start
engine 2 and place PWR lever to FLY
(TM 1-1520-238-CL). Operate until readings
stabilize.
Does open exist?
YES
Go to step 7.
NO
Replace NGB 2
(TM 1-1520-238-23).
