Refuel (Act 2) - Fails To Refuel In Manual Control

TASK 28-25-00-810-814-A
Refuel (Act 2) - Fails To Refuel In Manual Control

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

1. Possible Causes

FLSCU 3 [47QJ]
PROBE-FQI NO 2, ACT2 [66QT2]
RELAY-CTL HI LVL, IND ACT 2 [57QJ]
aircraft wiring
VALVE-REFUEL, ACT [41QU]
C/B-ACT1/CTL & SPLY [9QH]
C/B-ACT1/REFUEL & SPLY [33QU]
SWITCH-INDICATOR, ACT [24QH]
SW-REFUEL VLV CTL, ACT 2 (42QU)
ACTUATOR-FUEL TRANSFER VALVE, ACT [6QH]
VALVE-FUEL TRANSFER, ACT [165QM]
RELAY-TRANSFER VALVE CONTROL, ACT [21QH]
RELAY- INLET VALVE CONTROL, ACT1 [19QH]
RELAY-INLET VALVE CONTROL, ACT2 [20QH]
RELAY-SEQUENCE [18QH]
RELAY-POWER SUPPLY SWITCH [39QU]
ACTUATOR-FUEL INLET VALVE, ACT2 [5QH2]
VALVE-FUEL INLET, ACT2 [166QM2]
RELAY-REFUEL/TRANSFER CONTROL, ACT2 [36QU]
RELAY-REFUEL INHIBIT, ACT2 [38QU]
ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH]
RELAY-PRESSURIZATION CONTROL, ACT [28QH]
ACTUATOR-VENT VALVE, ACT2 [4QH2]
VALVE-VENT, ACT2 [167QM2]

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	MULTIMETER - STANDARD

B. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 28-28-00-810-801-A	Fuel Pumps - ACT Manual Transfer Pump 1QH System Malfunction
TSM TASK 28-28-00-810-801-A-01	Fuel Pumps - ACT Manual Transfer Pump 1QH System Malfunction (802VU ACT Relay Testbox)
TSM TASK 28-28-00-810-802-A	Fuel - ACT 1 Manual Transfer Failure (On The Ground)
TSM TASK 28-28-00-810-802-A-01	Fuel - ACT 1 Manual Transfer Failure (On The Ground) (802VU ACT Relay Testbox)
TSM TASK 28-46-00-810-832-A	ACT 2 HI LVL Indicator Lamp Does Not Come On When TEST Switch Set To LTS
TSM TASK 28-46-00-810-833-A	ACT 2 HI LVL Manual TEST
AMM 12-11-28-650-004	Pressure Refuel with Manual Control
AMM 12-11-28-650-005	Pressure Refuel without Electrical Power
AMM 28-25-00-710-003	Operational Test of the Refuel System
AMM 28-25-00-869-001	Fuel Transfer
ASM 282501
AMM 28-25-51-000-003	Removal of the Solenoid Valve
AMM 28-25-51-000-004	Removal of the Refuel Valve
AMM 28-25-51-400-003	Installation of the Solenoid Valve
AMM 28-25-51-400-004	Installation of the Refuel Valve
ASM 282801
ASM 282803
ASM 282804
AMM 28-28-33-000-001	Removal of the ACT Fuel Transfer-Valve
AMM 28-28-33-400-001	Installation of the ACT Fuel Transfer-Valve
AMM 28-28-34-000-001	Removal of the ACT Fuel Inlet Valve (166QM)
AMM 28-28-34-400-001	Installation of the ACT Fuel Inlet Valve (166QM)
AMM 28-28-35-000-001	Removal of the ACT Vent Shut-off Valve (167QM)
AMM 28-28-35-400-001	Installation of the ACT Vent Shut-off Valve (167QM)
AMM 28-28-53-000-001	Removal of the ACT Transfer-Valve Actuator
AMM 28-28-53-400-001	Installation of the ACT Transfer-Valve Actuator
AMM 28-28-54-000-001	Removal of the ACT Fuel Inlet Valve Actuator (5QH)
AMM 28-28-54-400-001	Installation of the ACT Fuel Inlet Valve Actuator (5QH)
AMM 28-28-55-000-001	Removal of the ACT Vent Shut-off Valve Actuator (4QH)
AMM 28-28-55-400-001	Installation of the ACT Vent Shut-off Valve Actuator (4QH)
AMM 28-28-56-000-001	Removal of the ACT Air Shut-Off Valve Actuator
AMM 28-28-56-400-001	Installation of the ACT Air Shut-Off Valve Actuator
ASM 284210
ASM 284601

3. Fault Confirmation
Subtask 28-25-00-865-052-A ** ON A/C NOT FOR ALL

A. Table of the circuit breakers referred to in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	ACT1/REFUEL & SPLY	33QU	L29
121VU	ACT2/REFUEL & SPLY	34QU	L28
121VU	ACT1/CTL & SPLY	9QH	P29
121VU	ACT2/CTL & SPLY	10QH	P28

Subtask 28-25-00-710-063-A ** ON A/C NOT FOR ALL

B. Test
(1) Make sure that you obey the steps in the Pressure Refuel with Manual Control AMM 12-11-28-650-004.

NOTE: It is not possible to refuel the ACT 2 if the P/BSW-FUEL/ACT/AUTO (24QH) is set to the FWD (pushed in), manual transfer position.

NOTE: The ACT 2 Inlet Valve Actuator (5QH2) will not open if the ACT 2 is full of fuel (high level sensor wet).

(2) Do the Operational Test of the Refuel System AMM 28-25-00-710-003.

NOTE: You can get more data of the ACT System in the:

Description and Operation (D and O) section of the Aircraft Maintenance Manual (AMM) Chap, 28-25-00, the Refuel Defuel System
AMM Chap, 28-28-00, the Additional Center Tank (ACT) Transfer System
AMM Chap, 28-42-00, the Fuel Quantity Indicating System (FQIS)
AMM Chap, 28-46-00, the Fuel Level Sensing System (FLSS)
Aircraft Schematic Manual (ASM), Refuel/Defuel System Valve Control ACT 1 ASM 282501
ASM, ACT XFR System, Inlet Valve ASM 282801
ASM, ACT XFR System, Transfer Valve ASM 282803
ASM, ACT XFR System, Vent Valves ASM 282804
ASM, FQIS, Monitoring ASM 284210
ASM, FLSS, High Level Refuel Control ASM 284601.

4. Fault Isolation
Subtask 28-25-00-810-063-B ** ON A/C NOT FOR ALL

A. Procedure
(1) If the ACT 2 HI LVL Indicator Lamp does not come on when the TEST Switch is set to LTS (lights):

do ACT 2 HI LVL Indicator Lamp Failure (Ref. TSM TASK 28-46-00-810-832).

(2) If the ACT 2 HI LVL Indicator Lamp does not change condition when the TEST Switch is set to HI LVL or, does not go off when the TEST switch is released (because the ACT 2 is not full):

do ACT 2 HI LVL Manual TEST Failure (Ref. TSM TASK 28-46-00-810-833) to trouble-shoot the FLSCU 3 [47QJ] and the PROBE-FQI NO 2, ACT2 [66QT2] system.

(3) If the fault continues, examine the ACT 2 fuel quantity on the FUEL System Display page.
(a) If the ACT 2 fuel quantity shows less than 80 kg (180 lb) (low level sensors dry):

go to Step (7).

(b) If the ACT 2 fuel quantity shows more than 80 kg (180 lb) (low level sensors wet):
1 Make sure that the C/Bs that follow are closed:

C/B-ACT 2/XFR VLV/AUTO CTL (10QH)
C/B-ACT 2/REFUEL/VLV (34QU).

NOTE: This step is necessary to make sure that the ACT 2 system and RELAY-SEQUENCE (18QH) are energized.

2 Do a Fuel Transfer from the ACT 2 to the center tank AMM 28-25-00-869-001.

NOTE: These steps have been included to check the ACT 2 Fuel Inlet Valve.
A fuel transfer of the ACT 2 fuel will make sure there is correct operation of:

the inlet valve
the inlet valve actuator
the inlet valve actuator aircraft wiring, for the open command, between the actuator and the RELAY-PANEL 802VU.

(4) If fuel can be transferred from or into the ACT 2:

go to Step (7).

(5) If the fuel from the ACT 2 cannot be transferred forward:
(a) Do the ACT Manual Transfer, Pump System Failure (Ref. TSM TASK 28-28-00-810-801).
(b) Do the ACT Manual Transfer (On The Ground Failure) (Ref. TSM TASK 28-28-00-810-802).
(6) Make sure that the C/Bs that follow are closed:

C/B-ACT 2/XFR VLV/AUTO CTL (10QH)
C/B-ACT 2/REFUEL/VLV (34QU).

(7) Make sure that the refuel panel door 192MB/522KB/622KB is open.
(8) Make sure that the SW-MODE SELECT/REFUEL/OFF/DEFUEL/XFR (3QU)) on the REFUEL/DEFUEL PANEL (800VU) is set to REFUEL.
(9) Make sure that the SW-REFUEL VALVE/OPEN/NORM/SHUT ACT 2 (42QU) on the ACT REFUEL/DEFUEL PANEL (801VU) is set to OPEN.
(10) With a MULTIMETER - STANDARD at the RELAY-PANEL (802VU) TEST connector 4068VC, do the four (4) tests that follow:
(a) Do a check ASM 282501 to see if a ground is available at pin C.

NOTE: Relay-Panel 802VU Input
A ground at pin C shows you that the ACT 2 has ullage (space) to receive fuel because the ACT 2 high level sensor is dry.

1 If the ground is available at the TEST connector pin C, go to Step (b).
2 If the ground is not available go to Step (11).
(b) Do a check ASM 282501 to see if 28VDC is available between pin D and an applicable ground.

NOTE: Relay-Panel 802VU Input
The 28VDC at pin D shows that the air shutoff valve actuator is closed and the ACT 2 vent valve actuator is open (their refuel positions).

1 If the 28VDC is available at the TEST connector pin D, go to Step (c).
2 If the 28VDC is not available go to Step (12).
(c) Do a check ASM 282801 to see if 28VDC is available between pin P and an applicable ground.

NOTE: Relay-Panel 802VU Output
The 28VDC at pin P is the open command to the actuator fuel inlet valve, ACT 2 (5QH2).

1 If the 28VDC is available at the TEST connector pin P, go to Step (d).
2 If the 28VDC is not available go to Step (15).
(d) Do a check ASM 282501 to see if 28VDC is available between pin M and an applicable ground.

NOTE: Relay-Panel 802VU Output
The 28VDC at pin M is the open command to the valve-refuel ACT (41QU).

1 If the 28VDC is available go to Step (13).
2 If the 28VDC is not available go to Step (14).
(11) If a ground is not available at the TEST connector 4068VC, pin C, continue as follows:
(a) Disconnect the free connector 4065VC-A from the RELAY-PANEL (802VU).
(b) With a multimeter do a check ASM 282501 to see if a ground is available at the free connector 4065VC-A, pin T.
(c) If the ground is not available:
1 Do a check of the RELAY-CTL HI LVL, IND ACT 2 [57QJ] and replace, if necessary.
2 Do a check of the aircraft wiring ASM 282501 and ASM 284601 between:

the FLSCU-3 (47QJ) rack connector AA, pin 8C and the free connector 4065VC-A, pin T (ACT 2 HI LVL (LS7) CHAN O/P)
the FLSCU-3 (47QJ) rack connector AA, pin 6C and the RELAY-CTL HI LVL, IND ACT 2 (57QJ), pin A
the RELAY-CTL HI LVL, IND ACT 2 (57QJ), pin 2 and the ground point DC1 (ground I/P for (LS7) CHAN RELAY O/P)
the RELAY-CTL HI LVL, IND ACT 2 (57QJ), pin Z and the ground point DC1 (relay control coil ground)
the RELAY-CTL HI LVL, IND ACT 2 (57QJ), pin X and the C/B-ACT2/REFUEL/VLV (34QU).

(d) Repair all the unserviceable wiring and connectors.
(e) Connect the free connector 4065VC-A to the RELAY-PANEL (802VU).
(f) Do the test given in Para. 3.B.(2).
(g) If the fault continues, do ACT 2 HI LVL Manual TEST Failure (Ref. TSM TASK 28-46-00-810-833).
(12) If 28VDC is not available at the TEST connector 4068VC, pin D, continue as follows:
(a) Disconnect the free connector 4065VC-A, from the RELAY-PANEL (802VU).
(b) Do a check of the aircraft wiring ASM 282501 between:

the free connector 4065VC-A, pin L and the aircraft to tank interface 7619VC2, pin 21
the ACT 2 aircraft to tank interface free connector 7619VC2-A, pin 21 and the Actuator-Vent Valve, ACT 2 free connector 4QH2-A, pin C.

(c) Repair all the unserviceable wiring and connectors.
(d) Connect the free connector 4065VC-A, to the RELAY-PANEL (802VU).
(e) Do the test given in Para. 3.B.(2).
(f) If the fault continues:

go to Step (15).

(13) If 28VDC is available at the TEST connector 4068VC, pin M, continue as follows:
(a) Get access to the Valve-Refuel, ACT (41QU).
(b) Disconnect the free connector 41QU-A from the VALVE-REFUEL, ACT (41QU).
(c) With a multimeter do a check ASM 282501 to see if 28VDC is available at the free connector 41QU-A, between the pins A (+ve) and C (-ve).

NOTE: The ground at pin C is only available if the Actuator Fuel XFR Valve (6QH) is in the closed position.

(d) If the:
1 28VDC (pin A) and the ground (pin C) are available at the free connector 41QU-A, in Step (13)(c):
a Do a check and replace if necessary the VALVE-REFUEL, ACT [41QU] AMM 28-25-51-000-003 and AMM 28-25-51-400-003.

NOTE: The resistance of the solenoid and internally connected diode is as follows:
With the multimeter +ve lead connected to pin A and the -ve lead connected to pin C, make sure the resistance is between 200 and 300 ohms.
With the multimeter +ve lead connected to pin C and the -ve lead connected to pin A, make sure the resistance is between 20 and 30 ohms.

b If the fault continues,

do a Pressure Refuel of the ACT without Electrical Power to check the VALVE-REFUEL, ACT (41QU) AMM 12-11-28-650-005.

c If necessary, replace the VALVE-REFUEL, ACT [41QU] AMM 28-25-51-000-004 and AMM 28-25-51-400-004.
2 28VDC is not available at the free connector 41QU-A, pin A in Step (13)(c):
a Do a check of the aircraft wiring ASM 282501 between:

the free connector 41QU-A, pin A and the RELAY-PANEL (802VU) free connector 4065VC-A, pin <J.

b Repair all the unserviceable wiring and connectors.
c Connect the free connector 41QU-A to the VALVE-REFUEL, ACT (41QU).
d Do the test given in Para. 3.B.(2).
e If the fault continues, go to Step (20).
3 A ground is not available at the free connector 41QU-A, pin C in Step (13)(c)
a Do a check of the aircraft wiring ASM 282501 between:

the free connector 41QU-A, pin C and the Actuator Fuel XFR Valve free connector 6QH-A, pin B.

b Repair all the unserviceable wiring and connectors.
c Connect the free connector 41QU-A to the VALVE-REFUEL, ACT (41QU).
d Do the test given in Para. 3.B.(2).
e If the fault continues, go to Step (15).
(14) If 28VDC is not available at the TEST connector 4068VC, pin M, continue as follows:
(a) Disconnect the free connector 4065VC-A, from the RELAY-PANEL (802VU).
(b) With a multimeter do a check ASM 282501 to see if 28VDC is available between free connector 4065VC-A:

pin <G (+ve) and pin <T or <M (-ve) (normal supply)
pin <S (+ve) and pin <T or <M (-ve) (refuel supply).

1 If the 28VDC is available:

go to Step (14)(c).

2 If the 28VDC is not available:
a Do a check of and replace, if necessary:

the C/B-ACT1/CTL & SPLY [9QH]
the C/B-ACT1/REFUEL & SPLY [33QU] .

b Do a check of the aircraft wiring ASM 282501 between:

the C/B-ACT1/XFR VALVE/AUTO CTL (9QH), terminal 2 and the free connector 4065VC-A, pin <G
the C/B-ACT1/REFUEL/VLV (33QU), terminal 2 and the free connector 4065VC-A, pin <S.

c Repair all the unserviceable wiring and connectors.
d Connect the free connector 4065VC-A to the RELAY-PANEL (802VU).
e Do the test given in Para. 3.B.(2).
(c) With a multimeter do a check ASM 282501 to see if a ground is available at the free connector 4065VC-A, pin <N.
1 If a ground is available:

go to Step (14)(d).

2 If a ground is not available:
a Do a check of ASM 282501 and replace if necessary:

the SWITCH-INDICATOR, ACT [24QH] .

b Do a check of the aircraft wiring ASM 282501 between:

the P/BSW-FUEL/ACT/AUTO (24QH), terminal A2 and the free connector 4065VC-A, pin <N.

c Repair all the unserviceable wiring and connectors.
d Connect the free connector 4065VC-A to the RELAY-PANEL (802VU).
e Do the test given in Para. 3.B.(2).
(d) With a multimeter do a check ASM 282501 to see if 28VDC is available at the free connector 4065VC-A, between pin S and an applicable ground.
1 If the 28VDC is available:

go to Step (15).

2 If the 28VDC is not available:
a Do a check of ASM 282501 and replace, if necessary:

the SW-REFUEL VLV CTL, ACT 2 (42QU), part of the REFUEL/DEFUEL PANEL (801VU).

b Do a check of the aircraft wiring ASM 282501 between:

the free connector 4065VC-A, pin S and the free connector 4067VC-A, pin K
the free connector 4067VC-A, pin D and the free connector 4023VC-A, pin <G.

c Repair all the serviceable wiring and connectors.
d Connect the free connector 4065VC-A to the RELAY-PANEL (802VU).
e Do the test given in Para. 3.B.(2).
(15) If the fault continues (when you think all the inputs to the relay-panel are correct):
(a) Examine the see/feel indicators of the actuators shown in the table that follows:
(b) If one of the actuators is not in the position given in the table:

go to the Fault Isolation Step indicated in the right (end) column.

ACTUATOR FUNCTIONAL DESIGNATION	FIN	CORRECT REFUEL POSITION	IF ACTUATOR NOT AT THE CORRECT REFUEL POSITION, GO TO THE TROUBLE-SHOOTING STEP SHOWN BELOW
FUEL XFR VALVE	6QH	CLOSED	(16)
FUEL INLET VALVE, ACT 2	5QH2	OPEN	(17)
AIR SHUT OFF VALVE	3QH	CLOSED	(18) SEE NOTE
VENT VALVE, ACT 2	4QH2	OPEN	(19)

NOTE: The Actuator Air Shutoff Valve (3QH), 28VDC command to CLOSE, can also be checked at the RELAY-PANEL (802VU) TEST connector 4068VC, pin Z.

(16) Actuator Fuel Transfer Valve (6QH) Refuel Trouble-shooting
(a) Disconnect the free connector 6QH-A from the ACTUATOR-FUEL XFR VALVE, ACT (6QH).
(b) Make sure the P/BSW-FUEL/ACT/AUTO (24QH) is set to AUTO (released out).
(c) With a multimeter do a check ASM 282803 to see if 28VDC is available at the free connector 6QH-A, between pins C (+ve), and E (-ve).
(d) If the voltage is correct, do a check of and replace, if necessary:
1 The ACTUATOR-FUEL TRANSFER VALVE, ACT [6QH] AMM 28-28-53-000-001 and AMM 28-28-53-400-001.
2 The VALVE-FUEL TRANSFER, ACT [165QM] AMM 28-28-33-000-001 and AMM 28-28-33-400-001.
(e) If the voltage is not correct, do a check of the aircraft wiring ASM 282803 between:

the Actuator Fuel XFR Valve free connector 6QH-A, pin C and the RELAY-PANEL (802VU) free connector 4065VC-A, pin <P
the Actuator Fuel XFR Valve free connector 6QH-A, pin E and the ground point DC1.

(f) Repair all the unserviceable wiring and connectors.
(g) Connect the free connector 6QH-A to the ACTUATOR-FUEL XFR VALVE, ACT (6QH).
(h) Do the test given in Para. 3.B.(2).
(i) If the fault continues:
1 Do a check of ASM 282803 and replace, if necessary:

the RELAY-TRANSFER VALVE CONTROL, ACT [21QH]
the RELAY- INLET VALVE CONTROL, ACT1 [19QH]
the RELAY-INLET VALVE CONTROL, ACT2 [20QH]
the RELAY-SEQUENCE [18QH]
the RELAY-POWER SUPPLY SWITCH [39QU] .

2 Do a check of the RELAY-PANEL (802VU) wiring ASM 282803 between the connector to relay and relay to relay lines, as shown in the table that follows:

NOTE: The circuit connections shown in the table are abbreviated, for example:

the connector 4065VC, pin <P is shown as 4065VC-<P
the RELAY-XFR VALVE CTL, ACT (21QH), terminal B3 is shown as RL 21QH-B3.

CONNECTOR-PIN	RELAY-TERMINAL TO	RELAY-TERMINAL
4065VC-<P	RL 21QH-B3
	RL 21QH-B2	RL 19QH-A3
	RL 19QH-A2	RL 18QH-A3
	RL 21QH-B2	RL 20QH-A3
	RL 20QH-A2	RL 18QH-A1
	RL 18QH-A2	RL 39QU-C2
	RL 39QU-C3	4065VC-<G
	RL 39QU-C1	RL 39QU-A2
	RL 39QU-A1	4065VC-<S

3 Repair all the unserviceable wiring and connectors.
4 Do the test given in Para. 3.B.(2).
(17) Actuator Fuel Inlet Valve (5QH2) Refuel Trouble-shooting
(a) Disconnect the free connector 5QH2-A from the ACTUATOR-FUEL INLET VALVE, ACT 2 (5QH2).
(b) With a multimeter do a check ASM 282801 to see if 28VDC is available at the free connector 5QH2-A, between pins A (+ve) and E (-ve).
(c) If the voltage is correct, do a check of and replace, if necessary:
1 The ACTUATOR-FUEL INLET VALVE, ACT2 [5QH2] AMM 28-28-54-000-001 and AMM 28-28-54-400-001.
2 The VALVE-FUEL INLET, ACT2 [166QM2] AMM 28-28-34-000-001 and AMM 28-28-34-400-001.
(d) If the voltage is not correct, do a check of the aircraft wiring ASM 282801 between:

the free connector 5QH2-A, pin A and the aircraft to tank break free connector 7619VC2-A, pin 15
the free connector 5QH2-A, pin E and the aircraft to tank break free connector 7619VC2-A, pin 5
the aircraft to tank break connector 7619VC2, pin 15 and the RELAY-PANEL (802VU) free connector 4065VC-A, pin G
the aircraft to tank break connector 7619VC2, pin 5 and the ground point DC1.

(e) Repair all the unserviceable wiring and connectors.
(f) Connect the free connector 5QH2-A to the ACTUATOR-FUEL INLET VALVE, ACT 2 (5QH2).
(g) Do the test given in Para. 3.B.(2).
(h) If the fault continues:
1 Do a check of ASM 282801 ASM 282803 and replace, if necessary:

the RELAY-INLET VALVE CONTROL, ACT2 [20QH]
the RELAY-REFUEL/TRANSFER CONTROL, ACT2 [36QU]
the RELAY-REFUEL INHIBIT, ACT2 [38QU]
RELAY-POWER SUPPLY SWITCH [39QU] .

2 Do a check of the RELAY-PANEL (802VU) wiring ASM 282801 and ASM 282803 between the connector to relay and relay to relay lines, as shown in the table that follows:

NOTE: The circuit connections shown in the table are abbreviated, for example:

the connector 4065VC, pin G is shown as 4065VC-G
the RELAY-INLET VALVE CTL, ACT 2 (20QH), terminal B3 is shown as RL 20QH-B3.

CONNECTOR-PIN	RELAY-TERMINAL TO	RELAY-TERMINAL
4065VC-G	RL 20QH-B3
	RL 20QH-B2	RL 36QU-B1
	RL 36QU-B2	RL 39QU-D2
	RL 20QH-X2	RL 38QU-A3

a Repair all unserviceable wiring and connectors.
b Do the test given in Para 3.B.(2).
(18) Actuator Air Shut Off Valve (3QH), Refuel Trouble-shooting
(a) Disconnect the free connector 3QH-A from the ACTUATOR-AIR SHUTOFF VALVE, ACT (3QH).
(b) With a multimeter do a check ASM 282804 to see if 28VDC is available at the free connector 3QH-A, between pins B (+ve), and E (-ve).
(c) If the voltage is correct, do a check of and replace, if necessary:

the ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH] AMM 28-28-56-000-001 and AMM 28-28-56-400-001.

(d) If the voltage is not correct, do a check of the aircraft wiring ASM 282804 between:

the Actuator Air Shutoff Valve free connector 3QH-A, pin B and the RELAY-PANEL (802VU) free connector 4065VC-A, pin <R
the Actuator Air Shutoff Valve free connector 3QH-A, pin E and the ground point DC1.

(e) Repair all the unserviceable wiring and connectors.
(f) Connect the free connector 3QH-A to the ACTUATOR-AIR SHUTOFF VALVE, ACT (3QH).
(g) Do the test given in Para. 3.B.(2).
(h) If the fault continues:
1 Do a check of ASM 282804 and replace, if necessary:

the RELAY-PRESSURIZATION CONTROL, ACT [28QH] .

2 Do a check of the RELAY-PANEL (802VU) wiring ASM 282804 between the connector to relay and relay to relay lines, as shown in the table that follows:

NOTE: The circuit connections shown in the table are abbreviated, for example:

the connector 4065VC, pin <R is shown as 4065VC-<R
the RELAY-PRESS CTL, ACT (28QH), terminal A1 is shown as RL 28QH-A1.

CONNECTOR-PIN	RELAY-TERMINAL TO	RELAY-TERMINAL
4065VC-<R	RL 28QH-A1
	RL 28QH-A2	RL 39QU-C2
	RL 39QU-C3	4065VC-<G
	RL 39QU-A1	4065VC-<S
	RL 39QU-A2	RL 39QU-C1

a Repair all the unserviceable wiring and connectors.
b Do the test given in Para. 3.B.(2).
(19) Actuator Vent Valve (4QH2), Refuel Trouble-shooting
(a) Disconnect the free connector 4QH2-A from the ACTUATOR-VENT VALVE, ACT 2 (4QH2).
(b) With a multimeter do a check ASM 282804 to see if 28VDC is available at the free connector 4QH2-A, between pins A (+ve) and E (-ve).
(c) If the voltage is correct, do a check of and replace, if necessary:
1 The ACTUATOR-VENT VALVE, ACT2 [4QH2] AMM 28-28-55-000-001 and AMM 28-28-55-400-001.
2 The VALVE-VENT, ACT2 [167QM2] AMM 28-28-35-000-001 and AMM 28-28-35-400-001.
(d) If the voltage is not correct:
1 Do a check of the aircraft wiring ASM 282804 between:

the free connector 4QH2-A, pin A and the aircraft to tank break free connector 7619VC2-A, pin 20
the free connector 4QH2-A, pin E and the aircraft to tank break free connector 7619VC2-A, pin 8
the aircraft to tank break connector 7619VC2, pin 20 and the ACTUATOR-AIR SHUT-OFF VALVE, ACT free connector 3QH-A, pin D
the aircraft to tank break connector 7619VC2, pin 8 and the ground point DC1.

(e) Repair all the unserviceable wiring and connectors.
(f) Connect the free connector 4QH2-A to the ACTUATOR-VENT VALVE, ACT 2 (4QH2).
(g) Do the test given in Para. 3.B.(2).
(h) If the fault continues, do a check of and replace, if necessary:

the ACTUATOR-AIR SHUTOFF VALVE, ACT [3QH] AMM 28-28-56-000-001 and AMM 28-28-56-400-001.

NOTE: This step is necessary because the control voltage for the Actuator Vent Valve 4QH2 comes from the Actuator Air Shutoff Valve 3QH only when it is completely closed.

No RELAY-PANEL (802VU) Internal Trouble-shooting is therefore required.

(20) Continued from Step (13)(d)2_e_
(a) Do a check of ASM 282501 ASM 282803 and replace, if necessary:

the RELAY-REFUEL/TRANSFER CONTROL, ACT2 [36QU]
the RELAY-POWER SUPPLY SWITCH [39QU] .

(b) Do a check of the RELAY-PANEL (802VU) wiring ASM 282501 and ASM 282803 between the connector to relay and relay to relay lines, as shown in the table that follows:

NOTE: The circuit connections shown in the table are abbreviated, for example:

the connector 4065VC, pin <J is shown as 4065VC-<J
the RELAY-REFUEL/XFR CTL, ACT 2 (36QU), terminal D1 is shown as RL 36QU-D1.

CONNECTOR-PIN	RELAY-TERMINAL TO	RELAY-TERMINAL
4065VC-<J	RL 36QU-D1
4068VC-M	RL 36QU-D1
	RL 36QU-D2 (-)via diode (+)	RL 36QU-B2
	RL 36QU-B2	RL 39QU-D2
	RL 39QU-D3	4065VC-H
	RL 39QU-A1	4065VC-<S
	RL 39QU-X1	4065VC-<S
	RL 36QU-X1	4065VC-S
	RL 36QU-X2	4065VC-T

(c) If necessary, replace the diode.
(d) Repair all the unserviceable wiring and connectors.
(21) Do the test given in Para. 3.B.(2).
(22) If the fault continues:

go to step (15).

[Rev.8 from Aug 2018] 2026.04.04 04:39:39 UTC