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TASK 72-58-45-300-801
1 . Replacement of Nickel-Graphite Coating.
A.This procedure gives instructions to repair the No. 4 bearing aft rotating seal (seal) by removing and replacing the nickel-graphite coating. Refer to Figure 901.
B.The following maximum repairable limits apply to this repair:
NOTE:
The information below gives maximum repairable limits for the applicable Inspection sections. The paragraphs are numbered the same as the manual Inspection sections.
NOTE:
For 72-58-45, Inspection 001, refer to TASK 72-58-45-200-801 (72-58-45, INSPECTION 001) .
(4)Visual Inspection.
(b)Do an inspection of the coating in area L for:
1Rubs or grooves:
Maximum repairable limit:
Any amount in the thermal spray coating, but not into the parent metal.
2Missing coating:
Maximum repairable limit:
Any amount with no damage to the parent metal.
C.The subsequent table gives a list of the part numbers that are applicable to this repair. All part numbers are applicable to all paragraphs unless specified differently.
 
Part Number(s)
 
2301M66P02  
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D.Proprietary/Complex Process Statement.
(1)None.
2 . Tools, Equipment, and Materials.
NOTE:
Repair sources can use equivalent alternatives for tools, equipment, and consumable materials, however, the repair source must demonstrate and document equivalency.
A.Tools and Equipment.
(1)Special Tools. None.
(2)Standard Tools and Equipment. None.
(3)Locally Manufactured Tools.
 
Description
Figure
 
Machining Fixture
902
B.Consumable Materials.
 
Code No.
Description
 
C10-012
Tape, Masking, High Temperature (masking tape)
C.Referenced Procedures.
 
ATA No.
Description
 
70-00-03
Machining Data
 
70-21-00
Chemical Cleaning
 
70-21-03
Cleaning Method No. 3 - Steam Cleaning
 
70-21-04
Cleaning Method No. 4 - Dry Abrasive Blast Cleaning
 
70-21-23
Cleaning Method No. 23 - Hand-Wipe Degreasing
 
70-23-00
Stripping Procedures
 
70-23-08
Stripping of Pure Aluminum and Nickel-Aluminum Bond Coatings
 
70-23-23
Removal of Coatings by High Pressure Water Stripping
 
70-24-00
Etching Procedures for Fluorescent-Penetrant Inspection
 
70-24-01
Swab Etching Procedure
 
70-32-00
Indirect Inspection Methods
 
70-32-03
Spot-Fluorescent-Penetrant Inspection
 
70-42-00
Blending and Removal of High Metal Procedures
 
70-49-00
Thermal Spraying
 
70-49-10
Thermal Spraying Nickel-Aluminum (Powder)
 
70-49-11
Thermal Spraying Nickel-Aluminum (Wire)
 
70-49-15
Thermal Spraying 85:15 Nickel-Graphite (Powder)
 
72-58-45
Inspection 001
D.Expendable Parts. None.
E.SPD Information.
(1)Locally Manufactured SPD. None
F.Special Solutions. None.
G.Test Specimens. Refer to TASK 70-49-10-340-011 (THERMAL SPRAYING NICKEL-ALUMINUM (POWDER)) , TASK 70-49-11-340-012 (THERMAL SPRAYING NICKEL-ALUMINUM (WIRE)) , and TASK 70-49-15-340-016 (THERMAL SPRAYING 85:15 NICKEL-GRAPHITE (POWDER)) .
3 . Dimensional Information.
Subtask 72-58-45-220-021
A.Refer to Figure 901 for specified dimensions and locations.
NOTE:
The dimensional data identified within this procedure was designed using inches as the base unit of measurement for dimensional values. The conversion to millimeters is rounded to one less decimal digit than inches. For minimum dimensions, converted values are rounded up. For maximum dimensions, converted values are rounded down. To avoid conversion errors, do not reconvert from millimeters to inches.
NOTE:
Reference dimensions do not require inspection.
 
Description
Minimum In-Process Dimension
Maximum In-Process Dimension
Minimum Finish Dimension
Maximum Finish Dimension
Reference Dimension
 
Dia J
10.05 in. (255.3 mm)
10.07 in. (255.7 mm)
9.9982 in. (253.955 mm)
10.0018 in. (254.045 mm)
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4 . Setup Information.
Subtask 72-58-45-350-001
A.Set-up the seal for machining. Refer to Figure 901, Figure 903, and as follows:
Subtask 72-58-45-930-001
(1)If necessary, make the machining fixture. Refer to Figure 902.
Subtask 72-58-45-350-002
(2)Install the machining fixture on the machine table. Refer to Figure 902 and as follows:
Subtask 72-58-45-220-022
(a)The runout of the machining fixture diameter FC must be 0.001 inch (0.02 mm) or less.
(b)The runout of the machining fixture surface FB must be 0.001 inch (0.02 mm) or less.
Subtask 72-58-45-350-003
(3)Install the seal on the machining fixture as follows:
(a)Make sure that the seal aft side points down.
Subtask 72-58-45-370-001
(b)If necessary, decrease the temperature of the seal to install it on the machining fixture.
Subtask 72-58-45-350-004
(c)Use the machining fixture diameter FD to do a check of the runout of the seal diameter B and as follows:
Subtask 72-58-45-220-023
1The runout of the machining fixture diameter FD must be less than 0.001 inch (0.02 mm).
Subtask 72-58-45-350-005
(d)Use the machining fixture diameter FD to do a check of the runout of the seal diameter K and as follows:
Subtask 72-58-45-220-024
1The runout of diameter K must be 0.005 inch (0.12 mm) or less.
5 . Procedure.
Subtask 72-58-45-160-004
A.Clean the seal. Refer to TASK 70-21-00-110-051 (CHEMICAL CLEANING) and TASK 70-21-03-160-001 (CLEANING METHOD NO. 3 - STEAM CLEANING).
Subtask 72-58-45-120-001
B.Alternative Procedure Available. Remove the nickel-graphite top coating and the nickel-aluminum bond coating from the seal as follows:
(1)Apply C10-012  masking tape to all areas that are external to the thermal spray coating area. Refer to Figure 904.
(2)Clean the seal to remove the nickel-graphite top coating. Refer to TASK 70-21-04-120-001 (CLEANING METHOD NO. 4 - DRY ABRASIVE BLAST CLEANING) and as follows:
(a)Use Method 4E.
(3)Remove the masking tape from the seal.
Subtask 72-58-45-160-003
WARNING:
USE EYE PROTECTION WHEN YOU USE COMPRESSED AIR TO CLEAN, COOL, OR DRY PARTS OR TOOLS. PARTICLES CAN CAUSE AN INJURY TO YOUR EYES. ENSURE COMPRESSED AIR PRESSURE IS LESS THAN 30 PSIG (207 KPA). DO NOT POINT COMPRESSED AIR AT YOURSELF OR OTHER PERSONS.
(4)Use clean, dry, oil-free compressed shop air to clean the seal.
(5)Apply C10-012  masking tape to all areas that are external to the thermal spray coating area. Refer to Figure 904.
Subtask 72-58-45-110-011
(6)Remove the nickel-aluminum bond coating from the seal. Refer to TASK 70-23-00-100-001 (STRIPPING PROCEDURES) and TASK 70-23-08-110-024 (STRIPPING OF PURE ALUMINUM AND NICKEL-ALUMINUM BOND COATINGS).
(7)Remove the masking tape from the seal.
Subtask 72-58-45-330-002
B.A.Alternative Procedure. Remove the nickel-graphite top coating and the nickel-aluminum bond coating from the seal. Refer to TASK 70-23-00-100-001 (STRIPPING PROCEDURES) and TASK 70-23-23-330-008 (REMOVAL OF COATINGS BY HIGH PRESSURE WATER STRIPPING).
Subtask 72-58-45-320-002
CAUTION:
DO NOT MACHINE INTO THE PARENT MATERIAL AND BELOW THE IN-PROCESS DIMENSIONS FOR DIAMETER J. DAMAGE TO THE SEAL CAN OCCUR.
B.B.Alternative Procedure. Machine the seal to remove the nickel-graphite top coating and the nickel-aluminum bond coating. Refer to TASK 70-00-03-800-004 (MACHINING DATA), Subtask 72-58-45-220-021 (paragraph 3.A.), Figure 901, and as follows:
NOTE:
Removal of parent material during machining can limit the future repairability of the seal.
Subtask 72-58-45-350-006
(1)Set-up the seal for machining. Refer to Subtask 72-58-45-350-001 (paragraph 4.A.).
(2)Machine diameter J to the in-process dimensions.
(3)Remove the seal from the machining fixture.
Subtask 72-58-45-220-025
C.Measure the seal diameter J. Refer to Subtask 72-58-45-220-021 (paragraph 3.A.), Figure 901, and as follows:
(1)If diameter J agrees with the in-process dimensions, do Subtask 72-58-45-110-012 (paragraph 5.D.) thru Subtask 72-58-45-160-005 (paragraph 5.M.).
(2)If there is remaining thermal spray coating and diameter J is less than the maximum in-process dimension, do Subtask 72-58-45-120-001 (paragraph 5.B.) again.
(3)If diameter J is more than the maximum in-process dimension, you cannot repair the seal with this procedure.
Subtask 72-58-45-110-012
D.Etch the exposed seal parent material in the thermal spray coating area. Refer to TASK 70-24-00-110-033 (ETCHING PROCEDURES FOR FLUORESCENT-PENETRANT INSPECTION), TASK 70-24-01-110-034 (SWAB ETCHING PROCEDURE), Figure 901, and as follows:
(1)Use Class C etchant.
Subtask 72-58-45-230-003
E.Do an inspection of the seal repair area. Refer to TASK 70-32-00-200-002 (INDIRECT INSPECTION METHODS), TASK 70-32-03-230-002 (SPOT-FLUORESCENT-PENETRANT INSPECTION), Figure 901, and as follows:
(1)Make sure that you remove all the thermal spray coating from the seal before you do the fluorescent penetrant inspection.
NOTE:
Areas with thermal spray coating will show up as background fluorescence.
(2)Use Class G penetrant.
(3)Indications are permitted as follows:
(a)They are a minimum of 0.50 inch (12.7 mm) apart.
(b)They are a maximum of 0.03 inch (0.7 mm) in length.
(c)They are 0.03-0.06 inch (0.8-1.5 mm) in length and are not interpreted as linear indications.
NOTE:
Linear indications are indications that are at least four times longer than they are wide.
Subtask 72-58-45-340-001
F.Alternative Procedure Available. Thermal-spray the seal and the test specimens. Refer to TASK 70-49-00-340-001 (THERMAL SPRAYING), TASK 70-49-10-340-011 (THERMAL SPRAYING NICKEL-ALUMINUM (POWDER)), Figure 901, Figure 904, and as follows:
(1)Apply C10-012  masking tape to the seal areas that you will not thermal-spray.
(2)Make sure that you do the preliminary operations specified in TASK 70-49-00-340-001 (THERMAL SPRAYING).
(a)Use the surface roughness limits for the nickel base material.
Subtask 72-58-45-360-001
(3)Apply the bond coating to the seal and the test specimens to a thickness of 0.004-0.008 inch (0.11-0.20 mm) and as follows:
(a)Make sure that you apply thermal spray coating to the test specimens at the same time, same spray angle, and to the same thickness as the seal.
(4)Overspray is not permitted.
Subtask 72-58-45-340-002
(5)Do all the quality assurance testing specified in TASK 70-49-10-340-011 (THERMAL SPRAYING NICKEL-ALUMINUM (POWDER)).
Subtask 72-58-45-340-003
F.A.Alternative Procedure. Thermal-spray the seal and the test specimens. Refer to TASK 70-49-00-340-001 (THERMAL SPRAYING), TASK 70-49-11-340-012 (THERMAL SPRAYING NICKEL-ALUMINUM (WIRE)), Figure 901, Figure 904, and as follows:
(1)Apply C10-012  masking tape to the seal areas that you will not thermal-spray.
(2)Make sure that you do the preliminary operations specified in TASK 70-49-00-340-001 (THERMAL SPRAYING).
(a)Use the surface roughness limits for the nickel base material.
Subtask 72-58-45-360-002
(3)Apply the bond coating to the seal and the test specimens to a thickness of 0.004-0.008 inch (0.11-0.20 mm) and as follows:
(a)Make sure that you apply thermal spray coating to the test specimens at the same time, same spray angle, and to the same thickness as the seal.
(4)Overspray is not permitted.
Subtask 72-58-45-340-004
(5)Do all the quality assurance testing specified in TASK 70-49-11-340-012 (THERMAL SPRAYING NICKEL-ALUMINUM (WIRE)).
Subtask 72-58-45-340-005
CAUTION:
MAKE SURE THAT YOU DO NOT GRIT-BLAST THE SEAL. DAMAGE TO THE BOND COATING CAN OCCUR.
G.Thermal-spray the seal and the test specimens. Refer to TASK 70-49-00-340-001 (THERMAL SPRAYING), TASK 70-49-15-340-016 (THERMAL SPRAYING 85:15 NICKEL-GRAPHITE (POWDER)), Subtask 72-58-45-220-021 (paragraph 3.A.), Figure 901, and as follows:
(1)If necessary, apply C10-012  masking tape again to the areas that you will not thermal-spray.
(2)Apply the top coating to the seal and the test specimens to a maximum as-sprayed thickness of 0.085 inch (2.15 mm) and to a sufficient thickness to machine the seal to the finish dimensions and as follows:
(a)Make sure that you apply thermal spray coating to the test specimens at the same time, same spray angle, and to the same thickness as the seal.
(3)Overspray is not permitted.
(4)Do all the quality assurance testing specified in TASK 70-49-15-340-016 (THERMAL SPRAYING 85:15 NICKEL-GRAPHITE (POWDER)).
(5)Carefully remove the masking tape from the seal.
Subtask 72-58-45-110-013
H.Clean the seal to remove all the remaining masking tape. Refer to TASK 70-21-00-110-051 (CHEMICAL CLEANING) and TASK 70-21-23-110-053 (CLEANING METHOD NO. 23 - HAND-WIPE DEGREASING).
Subtask 72-58-45-340-006
I.If the test specimens do not agree with the requirements specified in Subtask 72-58-45-340-001 (paragraph 5.F.) and/or Subtask 72-58-45-340-005 (paragraph 5.G.), do Subtask 72-58-45-160-004 (paragraph 5.A.) thru Subtask 72-58-45-110-013 (paragraph 5.H.) again.
Subtask 72-58-45-320-001
J.Machine the seal repair area to the finish dimensions. Refer to TASK 70-00-03-800-004 (MACHINING DATA), Subtask 72-58-45-220-021 (paragraph 3.A.), Figure 901, and as follows:
Subtask 72-58-45-350-007
(1)Set-up the seal for machining. Refer to Subtask 72-58-45-350-001 (paragraph 4.A.).
(2)Machine diameter J to the finish dimensions.
(3)Remove the seal from the machining fixture.
Subtask 72-58-45-350-008
K.If necessary, lightly blend the seal to remove all the irregular edges between the masking area and the thermal spray coating area. Refer to TASK 70-42-00-350-002 (BLENDING AND REMOVAL OF HIGH METAL PROCEDURES).
Subtask 72-58-45-220-026
L.Do a visual inspection of the thermal spray coating surface of the seal and do as follows:
(1)Lumps (berries), flaking, cracks, blisters, voids, and/or spattered particles of material that are unbonded or not atomized are not permitted.
NOTE:
Overspray is not permitted.
Subtask 72-58-45-160-005
M.Clean the seal. Refer to TASK 70-21-00-110-051 (CHEMICAL CLEANING) and TASK 70-21-03-160-001 (CLEANING METHOD NO. 3 - STEAM CLEANING).
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Figure 901   (Sheet 1 ) No. 4 Bearing Aft Rotating Seal - Nomenclature
* * * FOR ALL
Figure 901   (Sheet 2 ) No. 4 Bearing Aft Rotating Seal - Nomenclature
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Figure 901   (Sheet 3 ) No. 4 Bearing Aft Rotating Seal - Nomenclature
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Figure 902   Locally Manufactured Machining Fixture
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Figure 903   Machining Fixture - Setup Information
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Figure 904   No. 4 Bearing Aft Rotating Seal - Masking Area