Salvage Procedure for the Hydraulic Ejector Cylinder on some Articulated Trucks {5305} Caterpillar

Articulated Truck

730 EJECTOR (S/N: B1W1-UP)

740 EJECTOR (S/N: B1R1-UP; AZZ1-UP)

740B EJECTOR (S/N: L4F1-UP; T4S1-UP)

D400E Series II (S/N: APF1-UP)

Introduction

Table 1

Revision	Summary of Changes in SEBF9128
06	Updated Introduction
05	Updated Introduction
04	Changed Title to "Salvage Procedure for the Hydraulic Ejector Cylinder on some Articulated Trucks".
03	Included Salvage Procedure Specific to D400E Series II Trucks. Canceled SEBF8497 "Articulated Truck Ejector Cylinder Salvage".
02	Effectivity Added for 740B.

© 2018 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.

This Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

For questions or additional information concerning this guideline, submit a form for feedback in the Service Information System. To address an urgent issue, use the following resources to communicate your request to Caterpillar Repair Process Engineering:

• Caterpillar Dealer Technical Communicator

• Dealer Solution Network

• Caterpillar Technical Representative

• Knowledge Network

Canceled Part Numbers and Replaced Part Numbers

This document may not include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Summary

This guideline includes a repair process with illustrations. This document is specific to the salvage of D400E II, 730, and 740 Articulated Trucks Ejector cylinders. The repair includes machining a groove inside the various stages of the cylinder and adding a wear band to each stage. Wear Band Kits are available from Caterpillar. Wear Band Kit 322-2010 is available for the D400E II and 740. Wear Band Kit 322-2009 is available for the 730. Six cylinder group part numbers are affected by this procedure. Part numbers 177-2004, 191-5115, 217-5382 and 224-1176 for the D400E II and 740. Part numbers 270-4484 and 251-6381 for the 730.

Note: The ejector cylinder on the D400E II and 740 are four-stage. The ejector cylinder on the 730 is three-stage.

Important Safety Information

Illustration 1	g02139237

Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.

Improper operation, lubrication, maintenance, or repair of this product is dangerous. Improper methods could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair of this product, until you understand the operation, lubrication, maintenance, and repair information. Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

Hazards are identified by a safety alert symbol. Safety alert symbols are followed by a signal word such as "Warning" that is shown below.

Illustration 2	g01032906

The following is the meaning of the above safety alert symbol:

• Pay Attention!

• Become Alert!

• Your Safety is Involved.

The message that appears under the warning explains the hazard. The message will be written or pictorially shown.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and on the product are not all inclusive. If a tool, a procedure, a work method, or an operating technique that is not recommended by Caterpillar is used, ensure that it is safe for all personnel around the machine. Also ensure that the product will not be damaged or that the product will not be made unsafe by the operation, lubrication, maintenance, or repair procedures.

All of the information, specifications, and illustrations that are in this publication are based on information that was available at the time of publication. The following information could change at any time: specifications, torque, pressures, measurement, adjustments, illustrations and other items. These changes can affect the service that is given to the product. Obtain the most current and complete information before you start any job. Caterpillar dealers have the most current information that is available.

References

Table 2

References
Media Number	Title
RENR5176	"Ejector Cylinder - Disassemble"
SEBF9236	"Fundamentals of HVOF Spray for Reconditioning Components"
SEBF9238	"Fundamentals of Arc Spray for Reconditioning Components"
SEBF9240	"Fundamentals of Flame Spray for Reconditioning Components"

Cylinder Nomenclature

Refer to Illustrations 3 and 4 for cylinder nomenclature throughout the document.

Illustration 3	g01377688
Cylinder Nomenclature for the D400E II and 740 (1) Piston (2) Stage 3 (3) Stage 2 (4) Stage 1 (5) Housing

Illustration 4	g01406140
Cylinder Nomenclature for the 730 (1) Piston (2) Stage 2 (3) Stage 1 (4) Housing

The first step in the process after the cylinder is disassembled is to measure the outside diameter of each stage.

Outside Diameter Measurement

Illustration 5	g01377727

Measure the outside diameter (OD) of Stage 1, Stage 2, Stage 3 (740 and D400 only), and the Piston. Measure the stage at four locations along the length. Do not measure at the very end of each stage. Start measurements 76 mm (3 inch) from each end. Measure the stage at two positions 90 degrees from each other at all four locations. Record the dimensions in Table 3. Record the largest diameter for each stage in the right-hand column in Table 3.

Table 3

Outside Diameter Measurement Values
		Position 1	Position 2	Position 3	Position 4	Largest Diameter
Stage 1 OD	0°
	90°
Stage 2 OD	0°
	90°
Stage 3 OD (740 and D400 only)	0°
	90°
Piston OD	0°
	90°

Determine the Depth of New Groove

1. Record the largest diameter value from the right-hand column of Table 3 for the stage you are working on.

2. Add 6.5 mm (0.25 inch) to the dimension from Step 1. This is the correct inside diameter to machine for the new groove.

   Note: The 6.55 mm (0.258 inch) dimension is a sum of the target total clearance 0.15 mm (0.006 inch)plus the thickness of the wear band 3.2 mm (0.126 inch) X 2).

Determine the Position of New Groove

Illustration 6	g01377686
New Location of the Groove (A) 10 mm (0.394 inch) (B) 60 mm (2.362 inch) (1) U-Cup Groove

The position of the new wear band groove will start 10 mm (0.394 inch) behind the existing U-cup groove (1). The width of the groove will be 60 mm (2.362 inch) wide. All stages will be the same width. Refer to Illustration 6.

Machining

Illustration 7	g01377733

Do not start machining until all the measurements are recorded. Machine one groove in each of the four pieces. The 730 only has three pieces to machine. Machine one groove in the Housing, Stage 1, Stage 2 and Stage 3 ( 740 and D400 only). The depth of the groove is discussed under the section "Determine the Depth of New Groove" earlier in this document. The width of the groove is 60 mm (2.362 inch) for all stages. The location of the groove is discussed under the section "Determine the Position of New Groove" earlier in this document.

Note: All stages of this ejector cylinder have a hardened surface of at least Rockwell 65C. Select the appropriate tool to machine the grooves.

Note: Allow the cylinder to cool before taking final measurements. The inside diameter will shrink as the cylinder cools to ambient temperature.

Illustration 8	g01377693

Illustration 9	g01377694

Before machining begins, measure the inside diameter of the housing to determine the amount of material that needs to be removed. Measure the land with the spiral groove. Do not measure in the groove. The spiral groove can be seen in Illustration 8. Measure with an inside micrometer as shown in Illustration 9.

Selection of the Wear Band

Select the correct wear band from Tables 4 and 5 for each Stage.

Verify the wear band thickness before installation into each stage. All the wear bands should measure 3.2 mm (0.126 inch) thick. Measure each wear band with a rounded anvil micrometer. Refer to Illustrations 10 and 11.

Illustration 10	g01377742

Illustration 11	g01377744
Micrometer with rounded anvil (1) rounded anvil tip (2) flat tip

Table 4

Wear Band Selection Table for 740 and D400 only
Stage	Use this Wear Band Part Number. (from Wear Band Kit 322-2010)	Dimension of Wear Band (Thickness X ID)
Housing	322-2015	3.2 mm (0.126 inch) X 211.94 mm (8.344 inch)
Stage 1	322-2014	3.2 mm (0.126 inch) X 179.94 mm (7.084 inch)
Stage 2	322-2013	3.2 mm (0.126 inch) X 151.94 mm (5.981 inch)
Stage 3	322-2012	3.2 mm (0.126 inch) X 127.94 mm (5.037 inch)

Table 5

Wear Band Selection Table for 730 only
Stage	Use this Wear Band Part Number. (from Wear Band Kit 322-2009)	Dimension of Wear Band (Thickness X ID)
Housing	322-2013	3.2 mm (0.126 inch) X 151.94 mm (5.981 inch)
Stage 1	322-2012	3.2 mm (0.126 inch) X 127.94 mm (5.037 inch)
Stage 2	322-2011	3.2 mm (0.126 inch) X 104.94 mm (4.131 inch)

Second Repair

If a second repair of a cylinder is required, the measurements should be repeated to confirm the continued acceptability of all groove depths.

If one of the tube stages is replaced, the entire procedure must be repeated. The depth of the wear band groove must be calculated again to confirm compatibility between the new tube and previous components. Determine the proper depth for each groove according to the section earlier in this procedure. If the depth of the groove should be smaller, the new tube stage may not be compatible.

Table 6 lists the outside diameters and tolerances for each stage.

Table 6

Outside dimensions for 740 and D400 only
Stage 1	211.927 ± .023 mm (8.3436 ± 0.0009 inch)
Stage 2	179.927 ± .023 mm (7.0837 ± 0.0009 inch)
Stage 3	151.927 ± .023 mm (5.9814 ± 0.0009 inch)

Table 7

Outside dimensions for 730 only
Stage 1	151.927 ± .023 mm (5.9814 ± 0.0009 inch)
Stage 2	127.927 ± .023 mm (5.0365 ± 0.0009 inch)

D400E Series II Ejector Cylinder Salvage

The following sections pertain specifically to the ejector cylinder on D400E Series II articulated trucks.

Summary

Illustration 12	g02845477
174-2004 Implement Electronic Control Module Ejector Cylinder Fully Extended (1) 174-9256 Piston (2) 174-9257 Rod

This guideline provides procedures to inspect the internal O-ring groove in the 174-9256 Piston and the tube assembly diameter on the 174-9257 Eye Rod, which are part of the 174-2004 Implement Electronic Control Module. The 174-2004 Implement Electronic Control Module is used in the D400E Articulated Truck (AT). Specifications are provided for both the piston and the rod. If the piston and rod fail to meet the inspection criterion, the guideline also provides the recommended salvage procedures.

Machining the groove oversize salvages the O-ring groove in the 174-9256 Piston. Refer to Table 8 for a summary of the O-ring seals used with the piston.

Welding the diameter oversize and machining the rod diameter to the appropriate specifications salvage the tube assembly diameter of the 174-9257 Eye Rod.

Table 8

O-ring Seal Usage Summary
Condition	O-ring Seal Part Number
Original O-ring seal used in 174-9256 Piston.	174-9277
174-9256 O-ring groove meets inspection criteria.	095-1701
174-9256 O-ring groove fails to meet inspection criteria and is machined oversized.	217-5383

Inspection Procedure - 174-9256 Piston

Table 9

Required Tools
Tool	Caterpillar Part Number	Part Description	Qty
A	--	Internal Spring Caliper – Capable of reaching the bottom of the O-ring groove (Legs of calipers should have a 90-degree angle.)	1
B	--	External Micrometer	1
C	--	Precision Gage Blocks – Federal Specification GGG-G-15C Set Number 1	1

The internal O-ring groove in the 174-9256 Piston may exceed nominal specifications. Therefore, inspection of the 174-9256 Piston O-ring groove must be completed prior to the reassembly of the ejector cylinder. The nominal dimensions are presented in Illustration 14.

Illustration 13	g02845516
Measure the diameter of O-ring groove with a spring caliper or equivalent measuring device.

1. Measure the diameter of the O-ring groove. The diameter of the O-ring groove may be inspected with Tool A and Tool B or other suitable measuring devices.

   Note: Make sure Tool A reaches the bottom of the O-ring groove.

   Note: Inspection of the O-ring groove diameter may also be completed using the fabricated gage blocks detailed in the Fabricated Gage Block section, in this guideline.

2. Measure the width of the O-ring groove. The width of the O-ring groove can be inspected with Tooling C.

   Table 10 and Illustration 14 summarize the tolerances for the O-ring groove.

3. If the O-ring groove meets the nominal dimension specifications, complete the inspection of the 174-9257 Eye Rod. Proceed with reassembly of the 177-2004 Ejector Cylinder Gp.

   Note: If the O-ring groove is within the nominal specifications, the ejector cylinder can be assembled with a new 095-1701 O-Ring Seal. Refer to Table 8. The 095-1701 O-Ring Seal is made from a material with a higher hardness and should provide better resistance to tearing and wear.

4. If the O-ring groove does not meet the nominal dimensions presented in Table 10 and Illustration 14. The O-ring groove will require salvage in accordance with the procedures presented in the section "Salvage Procedure - O-ring Groove.

Table 10

O-ring Groove Nominal Dimensions for 174-9256 Piston
Dimension	Metric (mm)	SAE (inch)
Width	3.6 -0 +0.2	0.142 -0 +0.008
Diameter	45 -0 +0.1	1.772 -0 +0.004

Inspection Procedure - Dimensional Summary

Illustration 14	g02847795

Illustration 15	g02952217

Inspection Procedure - 174-9257 Eye Rod

Tube Assembly Inspection

Table 11

Required Tools
Tool	Caterpillar Part Number	Part Description	Qty
A	--	Internal Spring Caliper	1
B	--	External Micrometer	1
C	--	Precision Gage Blocks - Federal specification GGG-G-15C Set Number 1	1

Inspection of the 174-9257 Eye Rod to determine if the rod deviates from the nominal dimensions must be completed prior to reassembly.

Illustration 16	g02847784
Tube assembly chamfer must be clean and deburred. Inspect the first 100 mm (3.94 inch) of the tube assembly.

1. Closely inspect the tube assembly and chamfer on the end of the tube. The chamfer needs to be clean and deburred. The tube assembly should be smooth, clean, and free from damage. Inspection of the first 100 mm (3.94 inch) from the chamfer must be completed to ensure that the O-ring will not be damaged during reassembly.
   Show/hide table

   Illustration 17	g02847787
   Measure the OD of the tube assembly.

2. Measure the outer diameter of the tube assembly. Tool B or other suitable measuring device may be used to measure the tube assembly. The tube assembly nominal outer diameter dimension is 40 – 0 + 0.05 mm (1.576 – 0 + 0.002 inch).

3. Measure the inner diameter of the tube assembly. Tool A or other suitable measuring device may be used to measure the tube assembly. The tube assembly nominal inner diameter dimension is 31 - 0.1 + 0.0 mm (1.22 - 0.004 + 0.0 inch) to a depth of 35 mm (1.38 inch).

   The dimensions of the rod are depicted in Table 12 and Illustration 15.

4. Deburr the tube assembly using a suitable grit sand paper if necessary.

5. If the tube assembly does not meet the dimensional tolerances, the tube assembly will require salvage in accordance with the procedures and specifications provided in the section "Salvage Procedure - Rod Tube Assembly".

6. Following the completion of the necessary salvage procedures, reassemble the ejector cylinder using the appropriate O-ring seal. Refer to Table 8 and refer to Disassembly and Assembly Manual, "Ejector Cylinder – Assemble".

Table 12

174-9257 Rod Nominal Dimensions
Dimension	Metric (mm)	SAE (inch)
Outer Diameter	40 -0 +0.05	1.576 -0 +0.002
Inner Diameter	31 -0.1 +0.0	1.22 -0.004 +0.0

Rod Head Inspection

Wear may occur on the 174-9257 Eye Rod head when the cylinder stages return against the head face. This wear may be accelerated when debris accumulates on the cylinder stage ends. During normal service, debris may accumulate on the cylinder stage ends. The debris accumulation may be accelerated if any of the wiper seals are damaged. Generally, this type of wear will not affect performance of the 174-9257 Eye Rod. Refer to the illustrations below for examples of this type of wear.

Illustration 18	g02847982
This is an example of rod head wear. The rod may be reused.

Illustration 19	g02847984
This is an example of wear due to the cylinder stages contacting the rod head. Prior to reuse, debur and smooth the wear edges and remove corrosion.

Salvage Procedure - O-ring Groove

If the O-ring groove in 174-9256 Piston does not meet the dimensional tolerances represented in Table 10 and Illustration 14, an oversize O-ring groove may be machined into the piston.

The oversize salvage procedure will increase the width of the O-ring groove from 3.6 – 0 + 0.2 mm (0.142 – 0 + 0.008 inch) to 7.20 – 0 + 0.2 mm (0.283 – 0 + 0.008 inch). The increase in the O-ring groove width will be applied equally to either side of the existing O-ring groove.

The diameter of the O-ring groove will be increased from 45 – 0 + 0.1 mm (1.77 – 0 + 0.004 inch) to 48.7 – 0 + 0.062 mm (1.917 – 0 + 0.002 inch).

The machining parameters, required tools, and dimensions are summarized in Tables 13 through 17 and Illustration 20 and 21.

Note: The method of machining is dependent on the capabilities of the Dealership completing the repair. The machining methods presented herein have been proven to be effective and are recommended.

Ejector Cylinder Dimensional / Material Property Summary

Table 13

O-ring Groove Oversize Dimension Summary
	Nominal Dimension	Nominal Dimension Tolerance	Oversize Dimension	Oversize Dimension Tolerance
Diameter	45 mm (1.772 inch)	-0 +0.1 mm (0.004 inch)	48.7 mm (1.917 inch)	-0 +0.062 mm (+0.002 inch)
Groove Width	3.6 mm (0.142 inch)	-0 +0.2 mm (0.008 inch)	7.20 mm (0.283 inch)	-0 +0.2 mm (+0.008 inch)

Illustration 20	g02847998
Oversize O-ring groove dimensions

Table 14

Piston Material Properties
Surface Hardness	HRC50	Surface is nitride hardened to a case depth of 0.305 mm (0.012 inch).
Core Hardness	HRC43	Hardness reading taken at a depth of 0.305 mm (0.012 inch).

Salvage Procedure - Machining Parameter Summary

Table 15

Required Tools
Tool	Caterpillar Part Numbers	Part Description	Qty
A	--	Internal Spring Caliper	1
B	--	External Micrometer	1
C	--	Precision Gage Blocks – Federal Specification GGG-G-15C Set Number 1	1
D	8T-5096	Dial Indicator Test Group	1
E	--	Telescoping Gage	1

Table 16

Recommended Machining Parameters / Tooling
Rotational Speed	155 RPM
Feed	0.152 mm / rev. (0.006 in. / rev.)
Feed Rate	23.62 mm/min. (0.93 inch/min.)
Cutting Tool (Left Handed)	Valenite – VLG-4189L: Carbide PVD Coated: Material Group SV230 Sandvik – TLGP 4189L: Coated 225 Iscar – GIFI 5.28 – 0.20: Coating Layer: MTCVD
Tool Holder	Valenite – A16-VLER3 or equivalent Iscar – GHIR/L or equivalent

Illustration 21	g02848003
Recommended grooving insert – Valenite VLG3105L

Table 17

Recommended Grooving Insert Specifications – Valenite VLG4189L
A	11.51 mm (0.453 inch)
ANSI	1
B	16.15 mm (0.636 inch)
E	6.35 mm (0.250 inch)
Gage Diameter	9.53 mm (0.375 inch)
R	0.510/0.635 mm (0.020/0.025 inch)
T	6.48 mm (0.255 inch)
W	4.80 mm (0.189 inch)

Salvage Procedure - Hollow Spindle Lathe

Show/hide table

Serious injury or death can result from contact with rotating parts or pinch points. To avoid injury, rotating parts, such as grinders, superfinishers, and lathes, should only be operated if all guards and protective devices are properly installed and in good working order. All equipment should be operated according to the manufacturer instructions.

Show/hide table

NOTICE
Always wear safety glasses when performing and machining operation.

Show/hide table

Illustration 22	g02848007
Install the piston into the lathe.

1. Use a suitable lifting device to place 174-9256 Piston in a suitable lathe. The weight of the piston is 119 kg (262 lb).
   Show/hide table

   Illustration 23	g02848016
   Cardboard is used to protect the piston.

2. Carefully insert the piston into the lathe. Place cardboard at both ends of the hollow spindle to avoid damaging the piston.
   Show/hide table

   Illustration 24	g02848018
   Brass is used to protect the piston.

3. Install brass sleeves to prevent the chuck jaws from damaging the piston. Tighten the jaws to secure the piston in the lathe.

   Note: A soft jaw chuck or a phenolic ring can also be used to protect the piston.

   Show/hide table

   Illustration 25	g02848057
   TIR not to exceed 0.05 mm (0.002 inch) at the front or the back of the piston.

4. Determine the total indicator runout (TIR) of the piston. To determine TIR use Tooling D or other suitable tooling. TIR shall not exceed 0.05 mm (0.002 inch). Determine TIR for both ends of the piston.

   Note: For Step 5 through Step 9, assume that the VLG4189L Valenite insert is being used to complete the machining process.

   Show/hide table

   Illustration 26	g02848060
   Measure piston bore and use this dimension as a reference for the oversize machining operation.

5. Use Tool E and Tool B to measure the piston bore. Use the measurement as a reference during the machining operation. The bore should measure 40.05 + 0.05 mm (1.577 + 0.002 inch).
   Show/hide table

   Illustration 27	g02848064
   Touch off on the face of the piston.

6. Touch the cutting tool to the front face of the piston. If equipped, zero the digital position indicator.

7. Move the cutting tool into the bore of the piston distance Z and zero the digital readout. Determine distance Z in accordance with the following formula: Z = (d + W – X)/2.

   Z - Distance cutting tool should be moved into the piston bore to machine the O-ring groove.

   d - O-ring groove depth in cylinder; 25 mm (0.984 inch) – See Illustration 14.

   W - Width of grooving insert; 4.80 mm (0.189 inch)

   X - Difference between original groove width and oversize groove width; 3.6 mm (0.142 inch).

8. Position cutting tool within piston bore at the dimension obtained in Step 9, 40.05 + 0.05 mm (1.576 + 0.002 inch).
   Show/hide table

   Illustration 28	g02848116
   Digital readout prior to initiation of machining process.

   Note: If using a digital readout, the readings should be as follows: Axis X: 40.05 + 0.05 mm (1.576 + 0.002 inch) Axis Z: 0.0 (Refer to Step 7.)

   Show/hide table

   Illustration 29	g02848117
   Machine oversize O-ring groove.

9. Machine the O-ring groove oversize to achieve the new width and diameter. Table 13 provides the oversize width and diameter. Leave 0.254 mm (0.010 inch) of material to complete a finish cut.

   Final X Value: 48.7 mm (1.917 inch)

   Final Z Value: 2.40 mm (0.0945 inch)

   Show/hide table

   Illustration 30	g02857276
   Blow out chips during the machining procedure.

10. During the machining process, blow chips from the tool.

11. Deburr the edge of the oversize O-ring groove with 120 grit or equivalent sand paper.
    Show/hide table

    Illustration 31	g02857278
    Verify proper measurement of the O-ring groove using gage blocks.

12. Use Tool C to measure the width of the oversize O-ring groove. Verify that the groove is within specification by evaluating the upper and lower width tolerance. See Table 13 for the width tolerances.
    Show/hide table

    Illustration 32	g02857280
    Measure the diameter of the oversize O-ring groove using Tool E (telescoping gage) and fabricated gage blocks.

13. Measure the diameter of the oversize O-ring groove. The diameter can be measured using Tool A and Tool B. The diameter can also be measured using Tool E, fabricated gage blocks, and Tool B. See Table 13 for the diameter tolerances.

    Note: The fabricated gage block construction is detailed in the "Fabricated Gage Block Preparation" section of this manual.

14. Remove the piston from the lathe using a suitable lifting device. Be sure not to damage the piston surfaces during removal of the piston.

15. Reassemble the ejector cylinder using new O-ring seals. The redesigned seal part number is 217-5383 O-Ring Seal. Refer to Table 8 and refer to Disassembly and Assembly, "Ejector Cylinder – Assemble".

Salvage Procedure - Steady Rest / Lathe

Show/hide table

Serious injury or death can result from contact with rotating parts or pinch points. To avoid injury, rotating parts, such as grinders, superfinishers, and lathes, should only be operated if all guards and protective devices are properly installed and in good working order. All equipment should be operated according to the manufacturer instructions.

As an alternative to the hollow spindle lathe procedure, a standard lathe with a steady rest may be used. The machining operations are completed in the same manner as described in the preceding procedure. The use of a standard lathe and steady rest is detailed in the following steps.

Illustration 33	g02857281
Measure the piston to determine the appropriate location of the steady rest.

Illustration 34	g02857296
Locate the steady rest based on the measurement obtained in Step 1.

1. Measure the piston length to determine the appropriate location for the steady rest. The steady rest should be placed on the centerline of the undercut surface of the piston. The centerline of the undercut surface is located 1320.8 mm (52.00 inch) from the end of the piston.
   Show/hide table

   Illustration 35	g02857297
   Use a suitable lifting device to place the piston in the lathe.

2. Use a suitable lifting device to place the piston in the lathe. The weight of the piston is 118 kg (262.0 lb).

3. Use brass sleeves to protect the piston. Secure the piston in the chuck jaws.
   Show/hide table

   Illustration 36	g02857299
   The piston is placed on the steady rest. The steady rest supports are positioned on the undercut portion of the piston.

4. Place the piston in the steady rest and secure the piston in the steady rest.
   Show/hide table

   Illustration 37	g02857301

   Show/hide table

   Illustration 38	g02857302
   Measure TIR at both ends of the piston.

5. Use Tool D to measure the TIR at both ends of the piston. The TIR must not exceed 0.051 mm (0.002 inch).
   Show/hide table

   Illustration 39	g02857303
   Complete the O-ring groove machining procedure.

6. Machine the O-ring groove. The dimensions for the oversize O-ring groove are presented in Table 8.

Fabricated Gage Block Preparation

A fabricated gage block may be used to measure the diameter of the oversize O-ring groove. The fabricated gage block is prepared according to the following steps.

Illustration 40	g02857305
Fabricated gage.

Illustration 41	g02857306
Machine fabricated gage blocks.

1. Machine a cylindrical work piece on a lathe. The dimensions of the cylinder are as follows:

   OD = 48.7 mm (1.917 inch).

   ID = 41.08 mm (1.617 inch).

   Width = 6.35 mm (0.250 inch).

2. Cut the cylinder into thirds and break the edges with a file or sander. Make the cuts at 30 degrees, 150 degrees, and 270 degrees.

3. Use 2/3 of the cylinder as the fabricated gage blocks.

4. Measure the thickness of the fabricated gage with a Vernier Caliper. The thickness should be 3.81 mm (0.150 inch).

   Note: The wall thickness of the fabricated gage is 3.81 mm (0.150 inch). Therefore, add 3.81 mm (0.150 inch) to the measurement obtained in Step 13 of the section "Salvage Procedure - Hollow Spindle Lathe" in this document.

Salvage Procedure - Rod Tube Assembly

The tube assembly for 174-9257 Eye Rod has been found to have too small a diameter in some cases. To correct for the improperly sized diameter, the tube assembly can be salvaged by the following methods:

1. Build up the rod diameter with weld and machine to the correct diameter specification.

2. Build up the rod diameter using thermal spray processes and machine to the correct diameter specification.

To determine if the tube assembly requires salvage, complete the inspection procedure described in the section "Inspection Procedure - 174-9257 Eye Rod".

Weld Repair Procedure

Show/hide table

Serious injury or death can result from contact with rotating parts or pinch points. To avoid injury, rotating parts, such as grinders, superfinishers, and lathes, should only be operated if all guards and protective devices are properly installed and in good working order. All equipment should be operated according to the manufacturer instructions.

Show/hide table

NOTICE
Always wear safety glasses when performing and machining operation.

Show/hide table

Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can kill.

Welding Operator Qualifications

All repair-welding operators must be qualified for welding as outlined in the current ANSI.AWS D1.1 or D14.3 specifications.

The qualification will be for the welding process used in the position for repairing the rod. The welding operator must also have used the welding process within the past 6 months prior to the salvage procedure or be requalified.

Documentation must be maintained of the weld operator's qualifications.

Read and understand the manufacturer instructions and your employer safety practices. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gasses from your breathing zone and general area. Wear correct eye, ear, and body protection. Do not touch live electrical parts.

See American National Standard Z49.1, "Safety in Welding and Cutting" published by the American Welding Society, 2501 N.W. 7th Street, Miami, Florida 33125: OSHA Safety and Health Standards, 29 CFR 1910, available from U.S. Dept. of Labor, Washington, D.C. 20210.

Weld Process / Weld Consumables and Machining Parameter Summary

Table 18

E7018 Electrode Typical Mechanical Properties
	As Welded	Stress Relieved
Yield Point, psi (MPa)	68,000 (469)	58,000 (400)
Tensile Strength, psi (MPa)	78,000 (538)	74,000 (510)
% Elongation (2 in. or 51 mm)	30	34
% Reduction in Area	75.5	77
Dual Shield 7100 Ultra All Position Typical Mechanical Properties
Yield Point, psi (MPa)	78,500 (541)	72,000 (496)
Tensile Strength, psi (MPa)	90,000 (621)	87,000 (600)
% Elongation (2 in. or 51 mm)	27	28
% Reduction in Area	66	66

Table 19

Weld Process and Consumables
Caterpillar Part Number	Weld Process	Electrode/Wire Type	Diameter		AWS Specification
			mm	in.
--	SMAW	Atom Arc E7018	2.40	0.094	E7018
--	FCAW	Dual Shield 7100	1.15	0.045	E71T-1
Weld Parameters
Consumable	Weld Feed Speed		Amps	Volts	Polarity
	mm/sec	in./min
E7018 SMAW	--	--	275	28	Reverse
DS 7100 FCAW	76	180	275	28	Reverse

Table 20

Inspection Tools
Tool	Caterpillar Part Number	Part Description	Qty
B	--	External Micrometer	1

Table 21

Recommended Machining Parameters
Rotational Speed – Rough Cut	300 RPM
Feed – Rough Cut	0.254 mm / rev. (0.010 in. / rev.)
Feed Rate – Rough Cut	76.2 mm/min. (3.0 inch/min.)
Rotational Speed – Finish Cut	400 RPM
Feed – Finish Cut	0.15 mm/rev. (0.006 inch/rev.)
Feed Rate – Finish Cut	60 mm/min. (2.4 inch/min.)
Insert – Rough Cut Insert – Finish Cut	TNMG432 SNMG643
Turning Tool (TNMG432 Insert) Chamfer Tool (SNMG643 Insert)	MTJNR164 MSDNN166

Weld Procedure

The weld parameters and the weld consumables are summarized in Table 18 and Table 19. The inspection tooling is presented in Table 20 and the machining parameters are presented in Table 21.

The parts to be welded must be at a minimum temperature of 16° C (60.8° F) before and during welding. This temperature is required to avoid thermal shock and should not be confused with weld repair preheat requirements.

1. Remove all oil, grease, dirt, and inspection media from the weld area. Remove the surface oxides within 25.4 mm (1.00 inch) minimum of either side of the weld repair area.
   Show/hide table

   Illustration 42	g02857307
   Welded rod - typical example.

   Show/hide table

   Illustration 43	g02857309
   Welded rod.

2. Preheat the rod to 93.3° C (200° F) to avoid the formation of hard heat-affected zones and eliminate tendencies toward quench cracking on cooling.

3. Weld circumferential beads around the outside edge of the tube assembly and around the inside edge of the weld repair area. The inside edge shall be located at least 50 mm (2.0 inch) from the end of the tube.

   Note: Since weld distortion is a possibility, minimize the heat into the metal. The weld must be free of voids.

4. Weld 3.18 mm (0.125 inch) stringer beads longitudinally. Remove slag after every pass. To avoid heat buildup, stagger welds.

   Note: The weld procedure may also be completed circumferentially.

   Show/hide table

   NOTICE
   Welding the rod may contract the inner diameter. The rod internal diameter must meet the specifications presented in Table 12. After welding, measure the rod internal diameter.

   Show/hide table

   Illustration 44	g02857310
   TIR shall not exceed 0.05 mm (0.002 inch).

5. Use a lathe to machine the rod outside diameter. Establish TIR less than or equal to 0.05 mm (0.002 inch).

6. Complete the rough machining operation with the tooling and parameters specified in Table 21. Leave 1.5 mm (0.06 inch) of material to complete the finish machining.
   Show/hide table

   Illustration 45	g02857312
   Blend the welded surface into the original rod material.

   Note: Blend the inner portion of the welded area with the original rod material. Attempt to achieve a minimum parting line as shown in Illustration 42 and Illustration 43. Face the end of the rod to remove any excess weld. Machine the inner bore of the rod if any excess weld material remains.

7. Finish machine the rod. Machine two 0.76 mm (0.030 inch) passes to achieve a 32 micron finish.

   Note: To achieve the finish, it may be necessary to leave 0.03 mm (0.001 inch) polish allowance.

   Show/hide table

   Illustration 46	g02857314
   Machine a 45 degree chamfer.

8. Machine a 45 degree chamfer in the end of the rod.
   Show/hide table

   Illustration 47	g02857315
   Use Tool B, external micrometer, to measure the rod diameter.

9. Use Tool B to measure the diameter of rod.

   Note: If the rod internal diameter does not meet the specification, the internal diameter will be too small to allow usage of the 213-5138 Installation Tooling.

   Show/hide table

   Illustration 48	g02857319
   Machining tube assembly ID.

10. If the internal diameter is too small, the internal diameter should be machined to the specifications presented in Table 12. Complete the machining in accordance with the machining parameters described in Table 21.

11. Reassemble the ejector cylinder. Refer to Table 8 and refer to Disassembly and Assembly Manual, "Ejector Cylinder – Assemble".

Salvage Procedure - Thermal Spray (Flame Spray, Arc Spray, and HVOF)

As an alternative to the welding procedure, the rod can also be built up using flame spray, arc spray, or High Velocity Oxygen Fuel (HVOF). Refer to the following Reuse and Salvage Guidelines for information on these procedures.

• SEBF9240, "Fundamentals of Flame Spray for Reconditioning Components"

• SEBF9238, "Fundamentals of Arc Spray for Reconditioning Components"

• SEBF9236, "Fundamentals of HVOF Spray for Reconditioning Components"

Complete the machining procedures in accordance with Step 4 through Step 10 in the section entitled "Weld Procedure".

For complete information regarding thermal spray operations, contact the Cat Dealer Support Division.

Note: Only Cat dealers utilizing the appropriate thermal spray equipment at their facility are allowed access to the thermal spray applications.