Adjustment of the Trim Valve [IAE]

TASK 79-21-41-820-010-A
Adjustment of the Trim Valve

WARNING: DO NOT LET ENGINE OIL STAY ON YOUR SKIN FOR A LONG TIME. FLUSH THE OIL FROM YOUR SKIN WITH WATER. THE OIL IS POISONOUS AND CAN GO THROUGH YOUR SKIN AND INTO YOUR BODY.

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: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

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

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 370 and 290 lbf.in (4.18 and 3.28 m.daN )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 70-23-11-911-013-A	General Torque Tightening Techniques
TASK 71-00-00-710-012-B	Test No.3 : Idle Leak Check
TASK 71-00-00-860-010-B	Engine Operation Limits, Guidelines and Special Procedures
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TSM 77
Adjust the Trim Valve

3. Job Set-up
Subtask 79-21-41-941-051-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 79-21-41-010-052-A ** ON A/C NOT FOR ALL

B. Open the fan cowls (Ref. AMM TASK 71-13-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR.
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR.

4. Procedure
Subtask 79-21-41-820-050-B ** ON A/C NOT FOR ALL

A. Adjust the trim valve.

Adjust the Trim Valve ** ON A/C NOT FOR ALL

(1) Obtain corrected oil pressure at idle (Ref. AMM TASK 71-00-00-860-010). Record the corrected oil pressure.

NOTE: The trim valve adjustment has to be done only if oil pressure pump performance deterioration causes engine oil pressure to fall below limit (MOP). TSM 77 for the troubleshooting of the low MOP.

(2) Identify the trim valve located on the oil pressure pump and filter assembly.
(3) Measure and record the dimension L. Use a sliding caliper.
(4) Temporary identify relative position of trim valve to pump casting. Use marker.
(5) Adjust the trim valve.
(a) Hold the trim valve screw (2) with a suitable wrench and loosen the self locking nut (1). Turn counterclockwise to loosen the self locking nut.

NOTE: Rotation of the trim valve by 1/4 turn clockwise, increases the MOP approximately by 9 PSI at engine idle condition.

NOTE: The trim valve should be adjusted to obtain a corrected MOP not more than 10 PSI above the minimum required limit.

(b) Turn clockwise the trim valve screw (2) as necessary.
(c) Record the rotation amount of the trim valve screw.
(d) Hold the trim valve screw with a wrench and turn clockwise the self locking nut (1).
(e) TORQUE the locking nut to between 370 and 290 lbf.in (4.18 and 3.28 m.daN )

(Ref. AMM TASK 70-23-11-911-013).

Subtask 79-21-41-410-051-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR.
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(3) Remove the WARNING NOTICE(S).

Subtask 79-21-41-780-050-B ** ON A/C NOT FOR ALL

C. Do a check of corrected MOP
(1) Do an engine ground run at idle (Ref. AMM TASK 71-00-00-710-012).

NOTE: The engine oil temperature must be 93.3 deg.C or greater.

(2) Check and record the measured oil pressure at idle.
(3) Correct the oil pressure at idle.
(a) If corrected MOP is above limit, clear the engine for further service.
(b) If corrected MOP is still below limit, start procedure again.
(c) If minimum MOP cannot be achieved reject the pump.

[Rev.10 from 2021] 2026.04.02 06:39:52 UTC