Removal of the AFT Air-Intake Anti-Ice Valve (PRSOV1)

TASK 30-21-51-000-804-A
Removal of the AFT Air-Intake Anti-Ice Valve (PRSOV1)

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

FIN: 4010DN

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	CAP - PROTECTION
No specific	AR	COVER - PROTECTION
No specific	1	PLIERS - JAWED, SOFT
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
No specific	1	WRENCH - STANDARD

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
Air-Intake Anti-Ice Valves

3. Job Set-up
Subtask 30-21-51-941-064-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch, and
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 30-21-51-865-083-A

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
122VU	ANTI ICE/ENG/1	1DN1	X10
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
122VU	ANTI ICE/ENG/2	1DN2	W10

Subtask 30-21-51-010-079-A

C. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR

Subtask 30-21-51-040-056-A

D. Deactivation of the Thrust Reverser System for Ground Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 30-21-51-010-080-A

E. Open the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL
(3) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 30-21-51-020-059-A

CAUTION: DO NOT LOOSEN OR REMOVE THE BOLTS ATTACHED TO THE FORWARD INNER DUCT (36) AND THE ENGINE CASE WHEN YOU REMOVE/INSTALL PRSOV1. IF YOU DO NOT TIGHTEN/TORQUE THE BOLTS, THIS CAN CAUSE LEAKAGE OF HOT AIR FROM THE FORWARD INNER DUCT DURING THE ENGINE OPERATION.

A. Removal of the Aft Air-Intake Anti-Ice Valve (aft anti-ice valve) (1)

NOTE: This valve is also known as Pressure Regulating and Shut-Off Valve 1 (PRSOV1).

(1) Disconnection of the electrical connector (2):

CAUTION: USE ONLY SOFT-JAW PLIERS. METAL-JAW PLIERS CAN MAKE THE ELECTRICAL CABLE UNSERVICEABLE.

(a) Use PLIERS - JAWED, SOFT to disconnect the electrical connector (2) from the aft anti-ice valve (1).

POST SB LEAP-1A 72-0292

(2) Remove the bolt (6) from the clamp (7).
(3) Remove the electrical harness (4) from the clamp (7).

END POST SB LEAP-1A 72-0292

(4) Remove electrical harness (3) and electrical harness (4) from the spring clips (5).
(5) Remove the coupling (20) between the vent hose (9) and the aft anti-ice valve (1).
(6) Disconnect the vent hose (9) from the aft anti-ice valve (1).
(7) Remove the sense tube (12) as follows:
(a) Disconnect the sense tube (12) from the air-sense tube (13).
(b) Use a counter-wrench to hold the aft duct (10) port fitting.
(c) Use a second WRENCH - STANDARD to disconnect the sense tube (12) from the aft duct (10) senseline port fitting and remove the sense tube (12) from the engine.
(8) Remove the tube hose (11) as follows:
(a) Use a counter-wrench to hold the fitting on the aft anti-ice valve (1).
(b) Use a second WRENCH - STANDARD to disconnect the tube hose (11) from the fitting on the aft anti-ice valve (1).
(c) Use a counter-wrench to hold the fitting on the aft duct (10).
(d) Use a second WRENCH - STANDARD to disconnect the tube hose (11) from the fitting on the aft duct (10) and remove the tube hose (11) from the engine.
(9) Remove the muscle tube (21) as follows:
(a) Use a counter-wrench to hold the fitting on the forward anti-ice valve (17).
(b) Use a second WRENCH - STANDARD to disconnect the muscle tube (21) from the forward anti-ice valve (17) fitting.
(c) Use a counter-wrench to hold the fitting on the aft anti-ice valve (1).
(d) Use a second WRENCH - STANDARD to disconnect the muscle tube (21) from the aft anti-ice valve (1) and remove the muscle tube (21) from the engine.
(10) Remove the coupling (15) between the vent hose (9) and the vent tube (22), and remove the vent hose (9) from the engine.
(11) Remove the nut (14) and bolt (18) from the inboard strut (19) immediately aft of the forward anti-ice valve (17).
(12) Carefully move the free end of the strut (19) away from the aft duct (10).
(13) Remove the nut (33) and bolt (34) from the aft strut (35) immediately aft of the aft anti-ice valve (1).
(14) Carefully move the free end of the strut (35) away from the aft duct (10).
(15) Open and remove the V-band clamp (32) at the aft end the aft anti-ice valve (1).
(16) Open and remove the V-band clamp (37) at the forward end of the aft anti-ice valve (1).
(17) Loosen the V-band clamp (28) at the aft end of the forward anti-ice valve (17). If necessary, V-band clamp (28) may be fully opened and removed, but be careful not to lose or damage the E-seal within the V-band clamp (28).
(18) Remove the aft anti-ice valve (1) as follows:
(a) Carefully move the aft anti-ice valve (1) in the forward direction while carefully moving the aft duct (10) in the aft direction to disengage the key tab from the key slot.
(b) Turn the valve clockwise (ALF) to remove it from the engine.
(c) If you need more access you can remove the nut (30) and bolt (29) from the vertical strut (27) and the nut (26) and the bolt (24) from the strut (25) immediately aft of the forward anti-ice valve (17).
(d) If you need more access, you can remove bolts (23) which secure spring clip bracket (16) to aft duct (10) flange.
(19) Remove and discard the E-seal (31) from the aft end of the aft anti-ice valve (1).
(20) Remove and discard the E-seal (38) from the duct opening that is forward of the aft anti-ice valve (1) location.
(21) Install COVER - PROTECTION and CAP - PROTECTION on all the open ports, open tubes, open hoses, and connectors.

[Rev.10 from 2021] 2026.04.01 00:30:28 UTC