Procedure to Install Support Plates and Gussets to the Side of the Scraper Bowl on Certain 623H and 623K Wheel Tractor-Scrapers {0635, 0679, 6201} Caterpillar

Wheel Tractor-Scraper

623H (S/N: EJD1-105; DBF1-175)

623K (S/N: WTB1-213; WTM1-110)

Introduction

This Special Instruction details the procedure to reinforce the scraper bowl side spreader joints on certain 623H and 623K Wheel Tractor-Scrapers.

Safety Section

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

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Before any burning or welding on a machine, all electrical power must be disconnected at the source, and locked out/tagged out. Failure to do so may result in electrical component damage. The immediate area shall be rockdusted, and the required fire-fighting materials shall be immediately available. All required gas testing shall be conducted throughout the operation.

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When removing a major component or attachment, ensure that it is properly blocked or secured before removing mounting hardware. An assembly that is disconnected without proper blocking may shift or fall, resulting in serious injury or death of personnel or machine damage.

Reference Section

Disassembly and Assembly, UENR3465, "Scraper from Tractor - Separate"

Disassembly and Assembly, UENR3465 , "System Pressure - Release"

Special Instruction , REHS7194 , "Parking Brake Purge Procedure for Certain Wheel Tractor-Scrapers" for the H models.

Testing and Adjusting , UENR3457, "Brake System Air - Purge" for the K models.

Required Parts

Inspection Procedure

The spreader bar should be inspected on both sides often to ensure that there are no cracks initiating in this area. If any cracks are detected in this area, address the cracks immediately. If the cracks are allowed to propagate, the repairs will be much more evasive and substantial. Any cracks identified need to be fully excavated and rewelded. The following pictures are examples of cracks that may appear on the outside of the spreader tube connections.

Illustration 1	g06098956
Examples of cracks that may be identified on the welded connections of the spreader tube.

Illustration 2	g06099006
Examples of cracks that may be identified on the welded connections of the spreader tube.

Illustration 3	g06099012
Examples of cracks that may be identified on the welded connections of the spreader tube.

Rework Procedure to Repair Cracks

After inspection, if cracks are found, use the following rework procedures.

The tractor and scraper should be separated to expose the cracks completely (getting the draft arms out of the way). For additional information in separating and connecting the scraper from the tractor, refer to Disassembly and Assembly, UENR3465, "Scraper from Tractor - Separate".

1. Release hydraulic system pressure. Refer to Disassembly and Assembly, UENR3465 , "System Pressure - Release".
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   Illustration 4	g06099042

2. Install suitable blocks under each end section of the cutting edge.
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   Illustration 5	g06099044

3. Block the machine wheels on each side.

4. Support the machine in front, so no tipping occurs.
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   Illustration 6	g06099286

5. Install suitable blocks under the power train guard. See Illustration 6.
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   Illustration 7	g06099342

6. Support the draft frame on both sides in location of arrows. See Illustration 7.
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   Illustration 8	g06099466
   Right side of Bowl (1) 350-3175 Bracket (2) 469-9195 Control Harness As

7. Remove the 350-3175 Bracket (1) and disconnect the 469-9195 Control Harness As (2) on the right side of the bowl. See Illustration 8.
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   Illustration 9	g06099486
   (3) 352-9722 Tube As (4) 355-1650 Hose As (5) 355-1649 Hose As (6) 367-4855 Cable As (7) 352-9723 Tube As (8) 352-9726 Hose As (9) 352-9735 Hose As

8. Disconnect hoses and tubes on both front sides of the bowl and cap to limit contamination. See Illustration 9.
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   Illustration 10	g06099558

9. Disconnect and cap the hoses from the elevator drive motor. See Illustration 10.
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   Illustration 11	g06100029
   (10) 8T-4194 Bolt (11) 1J-3049 Bracket (12) 2T-0342 Pin As

10. Remove the 8T-4194 Bolt (10), 1J-3049 Bracket (11), and the 2T-0342 Pin As (12) on both sides. Free the lift cylinders from the bowl. See Illustration 11
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    Illustration 12	g06100042
    (13) 7X-0389 Bolts (14) 358-1206 Cap-Bearing

11. Remove the four 7X-0389 Bolts (13) holding the 358-1206 Cap-Bearing (14) on both sides of the bowl. See Illustration 12.

12. Separate the scraper from the machine.
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    Illustration 13	g06100140
    (15) 352-4736 Plate As

13. Remove the 352-4736 Plate As (15) on the left rear side of the machine. See Illustration 13.
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    Illustration 14	g06100134
    (16) 352-4739 Plate As

14. Remove the 352-4739 Plate As (16) on the right rear side of the machine. See Illustration 14.
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    Illustration 15	g06100516

15. Disconnect the hoses and harness on each side at the rear of the scraper. Cap the hoses to limit contamination. See Illustration 15.

16. Remove the 366-2055 Baffles from both sides in the rear so that the tubes and harness can be slid forward.

17. Remove the 440-0238 Baffles in front of the bowl and slide the tubes and harness as far forward as possible.

18. Slide a weld blanket around the tubes and harness as far inside the bowl side as possible. This blanket will protect the tubes and harnesses from the heat of welding.
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    Illustration 16	g06100542

19. Any cracks identified need to be fully excavated and rewelded. If the crack goes through the weld and/or parent material thickness, a backing strip will need to be utilized, no more than 6 mm (0.24 inch) thick. See Illustration 16.

Parts Removal Procedure

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Illustration 17	g06100944
(1) 342-0744 Plate (2) 352-4741 Plate

1. Remove the 342-0744 Plate (1) and 352-4741 Plate (2). These plates connect the spreader tube to the inside plate of the side wall. The plates will be scrapped so sacrifice the plates and do not gouge into the wall or spreader tube. Once the plates are removed, grind the area where the welds were. If there are any divots or gouges, fill and sand the areas as if there was never a repair. Repeat this same process for the opposite side. See Illustration 17.
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   Illustration 18	g06101055
   Location of the lift cylinder mounting plate to be removed.

2. Remove the 375-4733 Plate (3), this plate connects the lift cylinder mounting tube and the inside wall. This plate will be scrapped as well, so sacrifice this plate when gouging this plate off. Once the plate is removed grind the area where the welds were. If there are any divots or gouges when done, fill and sand the areas as if there was never a repair. Repeat this same process for the opposite side. See Illustration 18.
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   Illustration 19	g06101100
   (4) 7T-1099 Links

3. Remove the 7T-1099 Links (4), which are connected to the spreader tube on the right side of the machine. Once the links are removed grind the area where the welds were, if there are any divots or gouges, fill and sand the areas as if there was never a repair. See Illustration 19.

New Parts Installation Procedure

This procedure is for the strengthening of the 623H / 623K elevating bowl. Welders shall be qualified to AWS D1.1, D14.3 or comparable standard.

Illustration 20	g06101128

Illustration 21	g06100542
Examples of excavation needed to repair extensive cracks on ends of spreader tubes.

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Illustration 22	g06101154
Location of 507-7418 Plate on spreader tube at rear of machine. (1) 507-7418 Plate. (A) Red lines locate 8 mm (0.315 inch) Fillet welds. (B) 23 mm (0.9 inch). (C) 60 mm (2.36 inch).

1. Attach the 507-7418 Plate (1) on the spreader tube 23 mm (0.9 inch) (B) from the top of the tube and 60 mm (2.36 inch) (C) from the inside wall of the scraper bowl. Attach the plate with 8 mm (0.315 inch) (A) fillet welds. See Illustration 22. Repeat the procedure on the left-hand side, using the 507-7420 Plate.
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   Illustration 23	g06101481
   Location of 507-6668 Plate. (2) 507-6668 Plate (A) Red lines locate 8 mm (0.315 inch) Fillet welds. (D) 6 mm (0.24 inch). (E) 20 mm (0.79 inch).

2. Attach the 507-6668 Plate (2) on the spreader tube on the right- hand side of the bowl. The plate will be on the back side of the spreader tube and sticking 20 mm (0.79 inch) above of the spreader tube, touching the lift cylinder mounting tube. Attach the plate with an 8 mm (0.315 inch) fillet weld. See Illustration 23. Attach the front side of the 507-6668 Plate below the cylinder mounting tube with a 6 mm (0.24 inch) bevel weld and a 6 mm (0.24 inch) fillet weld over the bevel weld. See Illustration 23. Ensure that the plate is fully tacked on either side before fully welding. The weld circled above shall only be welded on the flat area of the plate, do not weld the radiuses. Repeat the procedure on the left-hand side, using the 507-7419 Plate.
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   Illustration 24	g06101851
   (1) 507-7418 Plate. (2) 507-6668 Plate (3) 507-7417 Plate (A) Red lines locate 8 mm (0.315 inch) Fillet welds.

3. Attach the 507-7417 Plate (3) between the 507-7418 Plate (1) and the 507-6668 Plate (2). See Illustration 24. Weld the triangular side of the plate touching the spreader tube using an 8 mm (0.315 inch) fillet weld. Weld the sides and bottom with an 8 mm (0.315 inch) fillet weld. Do not weld either of the cut outs of the 507-7417 Plate (3) or the drain hole. Ensure that the plate is fully tacked on either side before fully welding. See Illustration 24.
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   Illustration 25	g06101930
   (2) 507-6668 Plate (4) 507-7421 Plate (A) 8 mm (0.315 inch) (AA) 8 mm (0.315 inch)

4. Attach the 507-7421 Plate (4) will be placed over the slot weld of 507-6668 Plate (2). The 507-7421 Plate (4) will be approximately 20 mm (0.79 inch) from the top of the 507-6668 Plate (2) and tacked in place. Ensure that the plate is fully tacked on either side before fully welding, to ensure no movement during welding. Use an 8 mm (0.315 inch) fillet weld on the top and bottom, the verticals are an 8 mm (0.315 inch) (AA) bevel weld, care should be taken not to stop or start in the corners, also do not weld where the cut outs are in the corners. The same instructions can be used on the left-hand side, using the 507-9318 Plate. See Illustration 25.
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   Illustration 26	g06101939
   View of spreader tube from front of elevating bowl. (F) 78 mm (3.07 inch) (G) 64 mm (2.52 inch) (H) 34 mm (1.39 inch) (J) 162 mm (6.38 inch)

5. Install two 9R-2613 Weld Bosses on the spreader tube towards the right-hand side of the elevating bowl. Use a 5 mm (0.20 inch) fillet weld all the way around the bosses. See Illustration 26 for location of bosses.

Inspection

Once all welding is finished, use the attached inspection criteria and repair anything that does not pass.

Illustration 27	g06102293

Illustration 28	g06102295

Illustration 29	g06102296

Illustration 30	g06102289

Illustration 31	g06102297

Illustration 32	g06102300

1. Paint new plates and repaired areas with yellow 4C-4200 Paint.

Reassembly

1. Remove the weld blanket from around the tubes and harness.

2. Slide the tubes and harness to original position and replace the 440-0238 Baffles in front of the bowl and the 366-2055 Baffles in the rear of the bowl.
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   Illustration 33	g06100516

3. Uncap the hoses and connect the hoses and harness on each side at the rear of the scraper. See Illustration 33.

4. Slide the scraper back to position to be connected to the machine.
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   Illustration 34	g06100042
   (13) 7X-0389 Bolts (14) 358-1206 Cap-Bearing

5. Reassemble the four 7X-0389 Bolts (13) holding the 358-1206 Cap-Bearing (14) on both sides of the bowl. See Illustration 34.
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   Illustration 35	g06100029
   (10) 8T-4194 Bolt (11) 1J-3049 Bracket (12) 2T-0342 Pin As

6. Connect the 8T-4194 Bolt (10), 1J-3049 Bracket (11), and the 2T-0342 Pin As (12) on both sides of the bowl. See Illustration 35.
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   Illustration 36	g06099558

7. Uncap and connect the hoses to the elevator drive motor. See Illustration 36.

   Note: When breaking elevator pump or motor lines, make sure that lines are flushed of any debris.

   Refer to Special Instruction , REHS7194 , "Parking Brake Purge Procedure for Certain Wheel Tractor-Scrapers" for the H models. and Testing and Adjusting , UENR3457, "Brake System Air - Purge" for the K models.

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   Illustration 37	g06099486
   (3) 352-9722 Tube As (4) 355-1650 Hose As (5) 355-1649 Hose As (6) 367-4855 Cable As (7) 352-9723 Tube As (8) 352-9726 Hose As (9) 352-9735 Hose As

8. Uncap and connect the hoses and tubes on both front sides of the bowl. See Illustration 37.
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   Illustration 38	g06099466
   Right side of Bowl (1) 350-3175 Bracket (2) 469-9195 Control Harness As

9. Reconnect the harness from Step 7. Use two 7K-1181 Cable Strap, two 4P-7581 Clips, two 8T-4137 Bolts, and two 8T-4121 Hard Washers to stabilize the harness to the 2 bosses welded on in the welding procedure. Reassemble the bracket over the harness connection point using the hardware removed in Step 7. See Illustration 38.
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   Illustration 39	g06100140
   (15) 352-4736 Plate As

10. Reassemble the 352-4736 Plate As (15) on the left rear side of the machine. See Illustration 39.
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    Illustration 40	g06100134
    (16) 352-4739 Plate As

11. Reassemble the 352-4739 Plate As (16) on the right rear side of the machine. See Illustration 40

12. Start the tractor engine and remove all the blocking and supports. Exercise implements repeatedly to purge the air out of the hydraulics. Check hose connections for leaks.

    Note: Purge the parking brakes after the hoses are reconnected.

    Special Instruction , REHS7194 , "Parking Brake Purge Procedure for Certain Wheel Tractor-Scrapers" for the H models.

    Testing and Adjusting , UENR3457, "Brake System Air - Purge" for the K models.

13. Top off fluids where required.

After inspection, if there are no cracks, complete the following steps.

1. Perform Disassembly from section "Rework Procedure to Repair Cracks", Steps 13 through 17.

2. Follow "Parts Removal Procedure" section above.

3. Complete the "New Parts Installation Procedure" section above.

4. From the "Reassembly" section above, perform Steps 1 through 3 , then Steps 7 through 13.