407-MM-CH79

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CHAPTER 79 — ENGINE OIL SYSTEM

CONTENTS - MAINTENANCE PROCEDURES

Paragraph Chapter/Section Page Number Title Number Number





ENGINE OIL SYSTEM

79-1 Engine Oil System ............................................................ 79-00-00 379-2 Engine Oil System — Troubleshooting ...................... 79-00-00 379-3 Engine Oil System Tube — Flushing ......................... 79-00-00 379-4 Engine Oil System — Servicing ................................. 79-00-00 679-5 Engine Oil System — Prime Procedure ..................... 79-00-00 6

OIL TANK

79-6 Oil Tank ............................................................................ 79-00-00 779-7 Oil Tank — Removal............................................ 79-00-00 779-8 Oil Tank — Inspection ......................................... 79-00-00 779-9 Oil Tank — Installation......................................... 79-00-00 9

OIL COOLER

79-10 Oil Cooler.......................................................................... 79-00-00 1179-11 Oil Cooler Duct Assembly — Removal ................ 79-00-00 1179-12 Oil Cooler Duct Assembly — Inspection.............. 79-00-00 1179-13 Oil Cooler — External Cleaning ................................. 79-00-00 1379-14 Oil Cooler — Internal Cleaning .................................. 79-00-00 1379-15 Oil Cooler — Repairs ................................................. 79-00-00 1379-16 Oil Cooler Duct Assembly — Installation ............. 79-00-00 1379-17 Temperature Regulating Valve — Functional Test .... 79-00-00 1479-18 Oil Cooler Fan .................................................................. 79-00-00 1479-19 Oil Cooler Fan — Removal and Installation ............... 79-00-00 1479-20 Oil Cooler Fan — Cleaning ........................................ 79-00-00 14

ENGINE OIL SYSTEM COMPONENTS

79-21 Engine Oil Filter ................................................................ 79-00-00 1579-22 Engine Oil Filter — Removal and Installation............. 79-00-00 1579-23 Engine Oil Filter — Inspection and Test..................... 79-00-00 1579-24 Engine Oil Chip Detectors ................................................ 79-00-00 1579-25 Engine Oil Chip Detectors — Removal and Installation 79-00-00 1579-26 Engine Oil Chip Detectors — Inspection and Test..... 79-00-00 1579-27 Oil Temperature Bulb ....................................................... 79-00-00 1579-28 Oil Temperature Bulb — Removal and Installation .... 79-00-00 1579-29 Oil Temperature Bulb — Inspection and Test ............ 79-00-00 1579-30 Oil Pressure Transmitter................................................... 79-00-00 1579-31 Oil Pressure Transmitter — Removal and Installation 79-00-00 1579-32 Oil Pressure Transmitter —inspection and Test ........ 79-00-00 15

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FIGURES

Figure Page Number Title Number

79-1 Engine oil system ........................................................................................... 479-2 Engine oil system schematic .......................................................................... 579-3 Oil tank ........................................................................................................... 879-4 Oil cooler ........................................................................................................ 12

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ENGINE OIL SYSTEM

79-1. ENGINE OIL SYSTEM

The engine oil system (Figure 79-1) is a dry sump typelubrication system. The engine oil system includes anexternally mounted oil tank (3), a temperature bulb (4),a manually operated drain valve (5), and an oil cooler(9). The oil cooler is installed on top of the fuselage,behind the aft firewall. The lubrication oil is supplied toand from the engine through rigid and flexible tubes.

The oil tank supplies lubricating oil through the oil inlettube (6) to a gear-type pressure pump installed on theaft face of the accessory gear box. Oil under pressure(pressure oil) goes through the oil filter and a pressureregulating valve, through the oil pressure sensing port,to the four lubricating ports and the torquemeterpressure port. This oil lubricates the engine. Thepressure oil becomes scavenge oil and returns to thethree scavenge pumps located on the aft face of theaccessory gear box. The scavenge oil goes throughthe three scavenge pumps and becomes scavengereturn oil. The scavenge return oil goes through thechip detector, through the oil outlet tube (7), throughthe external oil filter, and through the oil outlet tube tothe oil cooler (9). The scavenge return oil passesthrough the oil cooler, through the oil scavenge tube(2) to the oil tank.

The engine oil pressure indication is supplied by the oilpressure transducer. The engine torque pressureindication is supplied by the engine torque transducer.Both of these components are installed on the engine.

For the engine oil system schematic, refer to Figure79-2.

For the description and the operation of the engine oilsystem, refer to the Rolls-Royce 250-C47B SeriesOperation and Maintenance Manual, PublicationCSP 21001.

79-2. ENGINE OIL SYSTEM —TROUBLESHOOTING

For the engine oil system troubleshooting procedures,refer to Rolls-Royce 250-C47B Series Operation andMaintenance Manual, Publication CSP 21001,Chapter 72-00-00.

79-3. ENGINE OIL SYSTEM TUBE — FLUSHING

1. Remove the aft fairing (Chapter 53).

CAUTION

MAKE SURE THAT YOU INSTALL CAPSAND/OR PLUGS (C-428) ON ALL OF THEOPEN PORTS OF THE ENGINE OILSYSTEM. THIS PREVENTSCONTAMINATION OF THE SYSTEM.

2. For the steps that follow, install caps and/or plugs(C-428) on all of the open ports of the engine oilsystem.

3. Disconnect and remove the oil scavenge tube (2,Figure 79-1) from the elbow on the oil tank (3) andfrom the ENG OIL OUT union on the oil cooler (9).

4. Disconnect and remove the oil inlet tube (6) fromthe elbow on the oil tank (3) and from the bulkheadunion on the aft firewall.

5. Disconnect and remove the oil outlet tube (7)from the union on the oil cooler (9) and from the aftfirewall bulkhead union.

6. Disconnect and remove the oil scavenge tubeand the oil inlet tube that go between the aft firewalland the engine (Chapter 71).

7. Use trichlorethane (C-380) and flush all of theremoved oil tubes.

Refer to BHT-ALL-SPM for specifications.

MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-030 Lubricating Oil

C-380 Trichorehane

C-428 Caps and/or Plugs

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Figure 79-1. Engine oil system

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Figure 79-2. Engine oil system schematic

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8. Use dry, filtered compressed air and dry all of theremoved oil tubes.

9. Use lubricating oil (C-030). Flush all of theremoved oil tubes until the oil comes out clean andfree of any remaining cleaning solvent.

10. Connect the oil scavenge tube and the oil inlettube between the engine and the aft firewall(Chapter 71).

11. Connect the oil outlet tube (7) on the ENG OIL INunion to the oil cooler (9) and to the bulkhead union onthe aft firewall.

12. Connect the oil inlet tube (6) to the elbow on theoil tank (3) and to the bulkhead union on the aftfirewall.

13. Connect the oil scavenge tube (2) to the ENG OILOUT union on the oil cooler (9) and to the union on theoil tank (3).

14. Install the aft fairing (Chapter 53).

79-4. ENGINE OIL SYSTEM — SERVICING

If the helicopter engine has stopped for more than 15minutes, dry motor the engine for 30 seconds. Thisscavenges any oil which could have drained into thegearbox. If you do not do this, a false high engine oilconsumption level indication is given, or you will puttoo much oil in the oil tank when you fill it.

For the servicing procedure for the engine oil system,refer to Chapter 12.

79-5. ENGINE OIL SYSTEM — PRIMEPROCEDURE

If you replace an engine, an engine oil system

component, or disconnect the oil inlet tube, removethe air in the engine oil system before you start theengine. To remove the air from the engine oil system,do the steps that follow:

CAUTION

DO NOT TRY TO START THE ENGINEBEFORE YOU REMOVE THE AIR FROMTHE OIL SYSTEM. IF YOU DO NOTREMOVE THE AIR FROM THE SYSTEM,YOU CAN CAUSE DAMAGE TO THEENGINE OR TO THE COMPONENTS.

1. If you replace the engine oil filter, fill the engine oilfilter cavity with engine oil. Refer to the Rolls-Royce250-C47B Series Operation and Maintenance Manual,Publication CSP 21001, Chapter 72-00-00.

2. If you replace an engine or another major

component, do the steps that follow:

a. Disconnect and remove the oil inlet tube (19,Figure 79-3) from the elbow (20) on the oil tank (27).

CAUTION

MAKE SURE THAT YOU INSTALL CAPSAND/OR PLUGS (C-428) ON ALL OF THE

OPEN PORTS OF THE ENGINE OILSYSTEM. THIS PREVENTSCONTAMINATION OF THE SYSTEM.

b. Fill the oil inlet tube (19) with enginelubricating oil (Chapter 12).

c. Remove the cap on the elbow (20) andconnect the oil inlet tube (19) to the elbow (20).

d. Fill the engine oil tank (27) with enginelubricating oil (Chapter 12).

Refer to BHT-ALL-SPM for specifications.

MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-428 Caps and/or Plugs

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79-6. OIL TANK

The oil tank (27, Figure 79-3) has a normal fluid capacity of 1.5 gallons (5.7 L). You can see the oil level through the sight gage (29) or measure the oil level with the cap and adapter assembly (28). A dipstick is attached to the cap and adapter assembly. The oil tank includes ports for the vent tube (24), the oil inlet tube (19), the oil scavenge tube (5), the oil temperature bulb (4), and for the oil tank manual drain valve (17).

79-7. Oil tank — removal

1. Remove the aft fairing assembly (Chapter 53).

2. Put a fluid resistant container under the oil tank drain port.

3. Open the oil tank manual drain valve (17, Figure 79-3) and drain the oil tank (27).

4. Disconnect and remove the oil tank vent tube (24) from the elbow (23).

5. Loosen the nut (25). Remove the elbow (23) and the packing (26) from the oil tank (27). Discard the packing.

6. Disconnect and remove the oil scavenge tube (5) from the elbow (6).


8. Remove the oil temperature bulb (4) and the packing (3) (Chapter 95).

9. Disconnect and remove the engine oil inlet tube (19) from the elbow (20).


11. Remove the clamp (15) from the oil tank drain tube (16). Remove the drain tube (16) from the oil tank manual drain valve (17).

12. Loosen the nut (14). Remove the oil tank manual drain valve (17) and the packing (18). Discard the packing.

13. Remove the clamp (12) from the scupper drain tube (13). Remove the scupper drain tube.

14. Remove the plug (9) and the packing (10) from the oil tank (27). Discard the packing.

15. Remove the four bolts (1) and the washers (2) from the forward and aft oil tank supports (11).

16. Remove the oil tank (27) from the forward and aft oil tank supports (11).

MAKE SURE THAT YOU INSTALL CAPS AND/OR PLUGS (C-428) ON ALL OF THE OPEN PORTS OF THE OIL TANK. THIS PREVENTS CONTAMINATION OF THE OIL TANK.

17. Seal all of the open lines and all of the open ports of the oil tank. Install caps and/or plugs (C-428).

79-8. Oil tank — Inspection

1. Examine the oil tank as follows:

a. Examine the oil tank for cracks or leaks in the welds.

b. Examine the oil tank for damage to the threads in the ports and for damage to the threads of the tubes.

c. Examine the oil tank for loose or missing attaching hardware.

d. Examine the oil tank for signs of damage to the flanges.

e. Examine the oil tank sight gage for damage and signs of leaks.

OIL TANK

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Figure 79-3. Oil tank

BHT-407-MM-9

f. Examine the oil tank filler cap and the scupper for damage and for signs of leaks.

2. Examine the forward and aft supports (11, Figure 79-3) for signs of cracks, for damage to the nutplates, and for security of the rivets.

3. Examine the manual drain valve (17) for proper operation. Examine the drain tubes (13 and 16) for signs of leaks.

4. For the repair procedures for the oil tank and its components, refer to the BHT-407-CR&O manual.

79-9. Oil tank — Installation

1. Put the oil tank (27, Figure 79-3) in position on the forward and aft supports (11). Use the four bolts (1) and the washers (2) and attach the oil tank to the supports.

2. Remove all caps and/or plugs (C-428) from the ports and the tubes of the oil tank.

NOTE

Use turbine oil (C-030) and lubricate the packings before you install them.

3. Install the packing (18) on the manual drain valve (17).

4. Install the manual drain valve (17) in the drain port of the oil tank (27). Attach the nut (14) to the manual drain valve.

5. Connect the drain tube (16) to the manual drain valve (17). Attach the clamp (15).

6. Install the packing (10) on the plug (9). Install the plug in the port of the oil tank (27).

7. Install the oil temperature bulb (4) (Chapter 95).

8. Install the scupper drain tube (13) on the oil tank (27). Attach the clamp (12).

9. Install the packing (22) on the elbow (20).

10. Install the elbow (20) on the port of the oil tank (27). Tighten the nut (21).

11. Install the engine oil inlet tube (19) on the elbow (20).


13. Install the elbow (23) in the vent port of the oil tank (27). Tighten the nut (25).

14. Install the vent tube (24) on the elbow (23).


16. Install the elbow (6) in the scavenge port of the oil tank (27). Attach the nut (7).

17. Install the oil scavenge tube (5) on the elbow (6).

18. Make sure that the handle of the manual drain valve (17) is in the horizontal position.

19. If the helicopter engine has stopped for more than 15 minutes, dry motor the engine for 30 seconds. This scavenges any oil which could have drained into the gearbox. If you do not do this, a false high engine oil consumption indication is given, or you will put too much oil in the oil tank when you fill it.

20. Fill the engine oil tank with engine lubricating oil (Chapter 12).

21. Install the cap and adapter assembly (28) in the oil tank (27).

22. Make sure that the tubes and the mating surfaces of the oil tank do not have leaks.

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79-10. OIL COOLER

The oil cooler (16, Figure 79-4) is installed on the duct assembly (15). This duct assembly is installed on the oil cooler blower between the aft firewall and the forward face of the engine oil tank (27, Figure 79-3). The oil cooler is a transmission oil cooler and an engine oil cooler. The tail rotor driveshaft drives the fan that supplies and moves the air through the oil cooler (Chapter 65). The oil cooler is a dual element heat exchanger. One heat exchanger cools the engine oil. The other heat exchanger cools the transmission oil. The oil cooler has a temperature regulating relief valve. This valve regulates the engine oil temperature. This valve starts to close at 160 °F (71 °C) and is fully closed at 178 °F (81 °C). If the system pressure goes above 25 pounds per square inch (PSI) the pressure relief part of the valve opens the valve fully.

79-11. Oil cooler duct assembly — Removal

1. Remove the aft fairing (Chapter 53).

2. Put a fluid resistant container under the oil tank drain port.

3. Open the oil tank manual drain valve (17, Figure 79-3) and drain the oil tank and the oil cooler.

4. Disconnect and remove the tube assembly (1, Figure 79-4) from the union (2).

MAKE SURE THAT YOU INSTALL CAPS AND/OR PLUGS (C-428) ON ALL OF THE OPEN PORTS OF THE ENGINE OIL SYSTEM. THIS PREVENTS CONTAMINATION OF THE SYSTEM.

5. Disconnect and remove the union (2) and the packing (3) from the oil cooler OIL OUT port. Discard the packing.

6. Disconnect and remove the tube assembly (4) from the reducer (5).

7. Remove the reducer (5) and the packing (6) from the OIL IN port. Discard the packing.


9. Remove the reducer (8) and the packing (9) from the XMSN IN port. Discard the packing.


11. Remove the reducer (11) and the packing (12) from the XMSN OUT port. Discard the packing.

12. Remove the 12 bolts (13) and the washers (14) from the duct assembly (15).

13. Remove the duct assembly (15) and the oil cooler (16) as one assembly from the oil cooler blower (17).

14. Remove the oil cooler (16) from the duct assembly (15) as follows:

a. Cut and remove the lockwire from the temperature regulating valve (20).

b. Remove the temperature regulating valve (20) from the port in the oil cooler (16).

c. Remove the packing (21) from the temperature regulating valve (20). Discard the packing.

d. Remove the 18 bolts (18) and washers (19) and remove the oil cooler (16) from the duct assembly (15).

79-12. Oil cooler duct assembly — Inspection

1. Examine the oil cooler (16, Figure 79-4) as follows:

a. Examine the oil cooler cores for signs of damage and for leaks.

b. Examine the oil cooler for signs of damage to the threads and to the mating surfaces of the ports.

OIL COOLER

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Figure 79-4. Oil cooler

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c. Examine the oil cooler fins for signs of damage. Make sure that the air passages are clean.

2. Examine the duct assembly (15) as follows:

a. Examine the duct assembly (15) for signs of damage, cracks, or dents.

b. Examine the duct assembly (15) for loose rivets.

c. Examine the duct assembly (15) for signs of damage to the mounting holes.

79-13. OIL COOLER — EXTERNAL CLEANING

1. Examine the exterior surfaces of the oil cooler for signs of blockage.

2. Clean the exterior surface of the oil cooler with solvent (C-304).

3. Dry the exterior surface of the oil cooler with dry filtered air.

79-14. OIL COOLER — INTERNAL CLEANING

1. Examine the inlet and the outlet ports of the oil cooler for signs of blockage.

2. Flush the oil cooler cores with solvent (C-304).

3. Dry the oil cooler cores with dry filtered compressed air.

79-15. OIL COOLER — REPAIRS

Repair of the oil cooler is not recommended by the supplier. If the oil cooler is damaged or if the oil cooler has been contaminated, replace the oil cooler.

79-16. Oil cooler duct assembly — Installation

1. Remove all of the protective covers from the oil cooler ports and from the oil cooler tubes.

2. For the applicable steps that follow, lubricate the packings with the correct oil before you install them. Lubricate the transmission tube packings with transmission lubricating oil. Lubricate the engine oil tube packings with engine lubricating oil.

3. Install the packing (21, Figure 79-4) on the temperature regulating valve (20).

4. Install the temperature regulating valve (20) in the port of the oil cooler (16). Use lockwire (C-405) and safety the temperature regulating valve (20).

5. Put the oil cooler (16) in position on the duct assembly (15). Use the 18 bolts (18) and the washers (19) and install the oil cooler.

6. Put the oil cooler (16) and the duct assembly (15) (as an assembly) in position on the oil cooler blower (17). Use the 12 bolts (13), the washers (14), and install the assembly.

7. Install the packing (12) on the reducer (11).

8. Install the reducer (11) in the XMSN OUT port of the oil cooler (16).

9. Connect the tube assembly (10) to the reducer (11).


11. Install the reducer (8) in the XMSN IN port of the oil cooler (16).



14. Install the reducer (5) in the OIL IN port of the oil cooler (16).


16. Install the packing (3) on the union (2).

17. Install the union (2) in the OIL OUT port of the oil cooler (16).

18. Connect the tube assembly (1) to the union (2).

19. Make sure that the handle of the manual drain valve (17, Figure 79-3) is in the horizontal position.

20. If the helicopter engine has stopped for more than 15 minutes, dry motor the engine for 30 seconds. This scavenges any oil which could have drained into the

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gearbox. If you do not do this, a false high engine oil consumption indication is given, or you will put too much oil in the oil tank when you fill it.

21. Fill the engine oil tank with engine lubricating oil (Chapter 12).

22. Install the cap and adapter assembly (28) in the oil tank.

23. Make sure that the tubes and the mating surfaces of the oil cooler do not have leaks.

24. Install the aft fairing (Chapter 53).

79-17. TEMPERATURE REGULATING VALVE — FUNCTIONAL TEST

1. Apply heat to a container of water. Make the temperature reach 160 °F (71 °C).

2. Put the temperature regulating valve in the container for five minutes.

3. Make sure the temperature regulating valve begins to close.

4. Increase the water temperature to 178 °F (81°C). Make sure that the temperature regulating valve closes fully.

5. Remove the temperature regulating valve from the container. Measure the expanded length of the valve. The minimum expansion length of the valve is 0.080 inch (2.03 mm). If the expanded length of the valve is less than 0.080 inch (2.03 mm), the valve is unserviceable. Replace the valve.

79-18. OIL COOLER FAN

For the description and the operation of the oil cooler fan, refer to Chapter 65.

79-19. OIL COOLER FAN — REMOVAL AND INSTALLATION

For the removal and the installation procedures for the oil cooler fan, refer to Chapter 65.

79-20. OIL COOLER FAN — CLEANING

For the cleaning procedure for the oil cooler fan, refer to Chapter 65.

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ENGINE OIL SYSTEM COMPONENTS

79-21. ENGINE OIL FILTER

For the description and the operation of the engine oilfilter, refer to Rolls-Royce 250-C47B Series Operationand Maintenance Manual, Publication CSP 21001,Chapter 72-00-00.

79-22. ENGINE OIL FILTER — REMOVAL ANDINSTALLATION

For the removal and the installation procedures for theengine oil filter, refer to the Rolls-Royce 250-C47BSeries Operation and Maintenance Manual,Publication CSP 21001, Chapter 72-00-00.

79-23. ENGINE OIL FILTER — INSPECTION ANDTEST

For the inspection and the test procedures for theengine oil filter, refer to the Rolls-Royce 250-C47BSeries Operation and Maintenance Manual,Publication CSP 21001, Chapter 72-00-00.

79-24. ENGINE OIL CHIP DETECTORS

For the description and the operation of the engine oilchip detectors, refer to the Chapter 96.

79-25. ENGINE OIL CHIP DETECTORS —REMOVAL AND INSTALLATION

For the removal and the installation procedures for theengine oil chip detectors, refer to Chapter 96.

79-26. 79-26. ENGINE OIL CHIP DETECTORS —INSPECTION AND TEST

For the inspection and the test procedures for theengine oil chip detectors, refer to Chapter 96.

79-27. OIL TEMPERATURE BULB

For the description and the operation of the oiltemperature bulb, refer to Chapter 95.

79-28. OIL TEMPERATURE BULB — REMOVALAND INSTALLATION

For the removal and the installation procedures for theoil temperature bulb, refer to Chapter 95.

79-29. OIL TEMPERATURE BULB — INSPECTIONAND TEST

For the inspection and the test procedures for the oiltemperature bulb, refer to Chapter 95.

79-30. OIL PRESSURE TRANSMITTER

For the description and the operation of the oilpressure transmitter, refer to Chapter 95.

79-31. OIL PRESSURE TRANSMITTER —REMOVAL AND INSTALLATION

For the removal and the installation procedures for theoil pressure transmitter, refer to Chapter 95.

79-32. OIL PRESSURE TRANSMITTER —INSPECTION AND TEST

For the inspection and the test procedures for the oilpressure transmitter, refer to Chapter 95.

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407-MM-CH79

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