S365C and S385C Demolition and Scrap Shears Jaw - Repair Caterpillar

General Guidelines for Buildup and Hard Surfacing

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Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. 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 cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

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Personal injury can result from flame cutting or welding on painted areas. The effect of gasses from burned paint is a hazard to the person doing the cutting or welding. Do not flame cut or weld on painted areas.

The steel that is used in Cat shears is strong and durable. However, this steel requires special attention during maintenance. Pay very close attention to the preheat and postheat instructions and follow the instructions exactly. Review the following guidelines for buildup and hardsurfacing the shear. Detailed instructions on maintaining specific areas of the shear are on the following pages. Contact your Cat dealer for further information.

Preheat

Before any thermal process is applied to the steel of the shear, including welding, tack welding, cutting with a torch, and air-arcing, preheat the area according to the following table.

Jaws should be welded at ambient temperatures at or above 15° C (60° F).

Always keep the burner head at a minimum of 250 mm (10 inch) away from the jaws to maintain the materials qualities. Preheat an area of at least 200 mm (8 inch) around the point that will be welded. After heating the area, wait for 3 minutes before measuring the temperature. Do not measure the temperature directly after removing the heat source. Measure preheat temperature at a distance of 75 mm (3 inch) away from the point that will be welded at the opposite side of the heated side. If using an infrared temperature meter, keep the meter 300 mm (12 inch) to 500 mm (19.5 inch) away from the jaws, to prevent inaccurate measurements. If using temperature-indicating sticks, use the correct stick for the range of temperatures 150° C (300° F) to 220° C (430° F).

Preheat must be uniform throughout the thickness of the material and maintained until all welding has been completed. Avoid cyclic heating (large temperature swings).

Localized gas torches or thermal strip blankets may be used for preheating.

Interpass

The temperature of the weld area must be between 150° C (300° F) to 220° C (430° F) before another weld pass may be made. If the temperature has dropped below the minimum temperature, the weld area should be heated again to the minimum temperature. If the temperature is above the maximum interpass temperature, the weld area must be allowed to cool slowly until the weld area is below the maximum temperature. Do not allow material to be heated above 220° C (430° F). Do not accelerate the cooling process. Accelerating the cooling process will result in increased brittleness of the material.

Cool Down

Wrap heat blankets around the welded jaws immediately after welding has ended. Do not remove the welding blankets until the temperature has dropped below 80° C (175° F). Cooling to below this temperature will typically take approximately 4 hours or more.

Plan to perform buildup and hard surfacing at the end of the day or when there will be adequate time for the welded areas to cool before putting the shear back into service.

Buildup Material

When building up the shear jaws, closely adhere to the Preheat and Interpass heating procedures. The proper buildup material for the jaws should conform to the following:

• AWS A5.18 70: ER70S

Hard surface Material

The steel that is used in Cat shears is strong and durable. Hard surfacing of a new unused jaw is not recommended. AVSpare recommends allowing shear jaws to work harder and wear before initial hard surfacing. Once the jaws have worn, the jaws should first be built up following the buildup procedure before hard surfacing. The hard surfacing weld material should match the following chemical properties:

Some products that meet these properties are:

• LINCOLN Wearshield 420

• ESAB OK Tubrodur 15.50

Handling and storage of weld materials

Follow the weld manufacturers instructions for handling and storage closely. Make sure that the electrodes or wire are free of moisture. Moisture can cause hydrogen-cracks and porosity in the weld and possibly the base metal beneath the weld.

Weld Quality

Quality and attention to the detail in welding can significantly affect the life of the shear. AVSpare strongly recommends that only qualified and certified welders perform this work. Ensure that the weld consumables and base materials are clean, dry, and free of grease, paint, dirt, or any foreign substance that may harm the weld.

Rigging-Moving Jaw Safety

When working in or near the jaw, a safety rigging must be installed to ensure that there is no unintended motion of the moving jaw. Apply rigging with at least 2500 kg (5500 lb) capacity between the moving jaw maintenance eye and rear housing lifting eye (moving jaw safety rigging).

Illustration 1	g06119307

Shear Wear Inspection / Build-Up

Inspection

1. Open the jaws of the shear, and place the shear heel on the ground.

2. Turn off the engine and relieve hydraulic pressure.

3. Install the shear rotation lock (if applicable)
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   Do not operate the work tool unless you have read and understand the instructions and warnings in the Operation and Maintenance Manual. Failure to follow the instructions or heed the warnings could result in machine or work tool damage, serious injury or death.

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   Personal injury or death can result from sudden work tool movement. Sudden movement of the work tool can cause injury to persons near the work tool. To prevent injury or death, make sure that the area around the work tool is clear of personnel and obstructions before operating the work tool.

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   Do not strike against the cutter with a hardened steel tool of any kind. The cutter may chip and cause severe injury.

4. Apply moving jaw safety rigging. Refer to Operation and Maintenance Manual, "Rigging-Moving jaw safety".

5. Identify areas of the jaw that have significant wear or damage and are in need of buildup.

Build-Up

1. Clean the areas where buildup is needed. Prepare the surface as needed to ensure that a good weld can be applied. Grind away any remaining hard surface material as needed. Do not apply build-up material to a hard surface material, because it will chip off during use.

2. Preheat the repair area. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on preheat.
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   NOTICE
   Ground cable should be attached directly to the component being welded. Grounding to other places on the shear could result in arcing through bearing surfaces. This could lead to premature failure of the shear.

3. Using AWS 5.18 ER70S weld material, build up to original shape. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on interpass temperature. Weld beads should run longitudinal to the shear jaw as shown in Illustrations 2, 3, and 4.
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   Illustration 2	g06115525

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   Illustration 3	g06115527

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   Illustration 4	g06115531

4. Final weld surfaces should be flush with, or approximately 2 mm (0.08 inch) below the blade or piercing tip surfaces.

5. Allow the shear to cool before placing back into service. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on proper cooling.

Hard Surfacing of the Shear Jaws

1. Ensure that all jaw surfaces have been properly built up before applying hard surfacing. Refer to Operation and Maintenance Manual , "Shear Wear Inspection / Build-up".

2. Open the jaws of the shear, and place the shear heel on the ground.

3. Turn off the engine and relieve hydraulic pressure.

4. Install the shear rotation lock (if applicable).
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   Do not operate the work tool unless you have read and understand the instructions and warnings in the Operation and Maintenance Manual. Failure to follow the instructions or heed the warnings could result in machine or work tool damage, serious injury or death.

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   Personal injury or death can result from sudden work tool movement. Sudden movement of the work tool can cause injury to persons near the work tool. To prevent injury or death, make sure that the area around the work tool is clear of personnel and obstructions before operating the work tool.

   Show/hide table

   Do not strike against the cutter with a hardened steel tool of any kind. The cutter may chip and cause severe injury.

5. Apply moving jaw safety rigging. Refer to Operation and Maintenance Manual, "Rigging-Moving jaw safety".

6. Identify areas of the jaw where hard surfacing is required.

7. Clean the areas where hard surfacing is required. Prepare the surface as needed to ensure that a good weld can be applied.

8. Preheat the repair area. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on preheat.
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   NOTICE
   Ground cable should be attached directly to the component being welded. Grounding to other places on the shear could result in arcing through bearing surfaces. This could lead to premature failure of the shear.

9. Apply single pass welds with a height of approximately 3mm. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on hard surfacing material selection.

10. Apply welds beads in the direction and locations shown in Illustrations 5, 6, and 7
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    Illustration 5	g06115963
    (2) Staggered weld stops (3) Min 15mm from throat (4) Min 15mm edge of material

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    Illustration 6	g06115964
    (2) Staggered weld stops (3) Min 15mm from throat (4) Min 15mm edge of material

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    Illustration 7	g06115966

11. Do not apply weld within 15mm of the edge of the material.

12. Do not apply weld closer to the throat of the shear than as shown in Illustrations 5, 6, and 7. Stagger the ends of the welds as shown. Weld beads should be no closer than 15 mm to the end of the blade pocket

13. No weld stops are allowed in the apex of either the moving jaw or the fixed jaw.

14. Allow the shear to cool before placing back into service. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on proper cooling.

Heel Plate Inspection / Build-up

Inspection

Note: The heel plate (1) of the shear can experience excessive wear in some applications. If it is allowed to wear beyond acceptable limits structural failure can occur in the lower jaw

1. Inspect the heel plate (1) for excessive wear. Heel plate (1) should be a minimum of 20mm thick and edges should extend a minimum of 10mm beyond the base material of the jaw. If these minimums are not met build-up is required.
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   Illustration 8	g06115533
   (1) Heel plate (A) 20mm min

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   Illustration 9	g06115955
   (B) 10mm min

2. Identify areas of the heel plate (1) that have significant wear and are in need of buildup.

Build-up

1. Clean the areas where buildup is needed. Prepare the surface as needed to ensure that a good weld can be applied. Grind away any remaining hard surface material as needed. Do not apply buildup material to a hard surface material, because it will chip off during use.

2. Preheat the repair area. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on preheat.
   Show/hide table

   NOTICE
   Ground cable should be attached directly to the component being welded. Grounding to other places on the shear could result in arcing through bearing surfaces. This could lead to premature failure of the shear.

3. Using AWS 5.18 ER70S weld material, build up to original shape. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on interpass temperature. Weld beads should run in the direction shown in Illustrations 10, and 11
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   Illustration 10	g06115956

4. Allow the shear to cool before placing back into service. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on proper cooling.

   Note: If the heel plate is worn significantly, it may be easier to replace it than repair with build-up. Refer to parts manual for appropriate part number.

Heel Plate - Replace

1. Air arc the perimeter welds of the heel plate to remove.
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   Illustration 11	g06115958

2. Clean the heel plate area. Prepare the surface as needed to ensure that a good weld can be applied.

3. Bolt the new heel plate in with the cross blade and tack weld in place

4. Preheat the repair area. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on preheat.
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   NOTICE
   Ground cable should be attached directly to the component being welded. Grounding to other places on the shear could result in arcing through bearing surfaces.This could lead to premature failure of the shear.

5. Complete 12 mm fillet weld along perimeter of the heel plate.

6. Allow the shear to cool before placing back into service. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on proper cooling.

Tip Pocket Inspection / Repair

Inspection

It is EXTREMELY important that the piercing tips fit without excessive clearance within the piercing tip pocket. Excessive clearance can result in premature loosening of the piercing tip bolts or tip failure.With a high number of high force loads the base material of the pocket can deform and will need to be repaired to maintain the tight fit.

1. Open the jaws of the shear, and place the shear heel on the ground

2. Turn off the engine and relieve hydraulic pressure

3. Install the shear rotation lock (if applicable).
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   Do not operate the work tool unless you have read and understand the instructions and warnings in the Operation and Maintenance Manual. Failure to follow the instructions or heed the warnings could result in machine or work tool damage, serious injury or death.

   Show/hide table

   Personal injury or death can result from sudden work tool movement. Sudden movement of the work tool can cause injury to persons near the work tool. To prevent injury or death, make sure that the area around the work tool is clear of personnel and obstructions before operating the work tool.

   Show/hide table

   Do not strike against the cutter with a hardened steel tool of any kind. The cutter may chip and cause severe injury.

4. Apply moving jaw safety rigging. Refer to Operation and Maintenance Manual, "Rigging-Moving jaw safety".

5. With a new piercing tip set and dowels installed, inspect the clearances of the mating surfaces. The clearance should be no more than 0.2mm.
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   Illustration 12	g06115968
   (C) 0.2mm max

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   Illustration 13	g06115969
   (C) 0.2mm max

6. If repair is needed, remove the tips and position the shear so that the surfaces that need repair are in a good welding position

Repair

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Illustration 14	g06115973

1. Turn off the engine and relieve hydraulic pressure.

2. Install the shear rotation lock (if applicable).

3. Clean the area where repair is required.

   Note: If multiple surfaces are in need of repair, it is recommended to work on one surface at a time. Prepare the surface as needed to ensure that a good weld can be applied.

4. Preheat the repair area. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on preheat.

5. Using AWS A5.18 ER70S weld material, apply small single pass welds with a maximum height 3mm. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on build-up material selection.
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   Illustration 15	g06116022

6. Grind the surface smooth ensuring not to grind to the base material. Wear proper eye and hand protection for grinding.
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   Illustration 16	g06115977

7. With new dowels in place, install the piercing tip to check fit. If the tip does not fit observe the location of the interference and grind this area the appropriate amount to allow a fit. Once the tip is installed, check that the clearance is no more the 0.2mm. If needed repeat from step 11.

   Note: Wear proper hand protection as the jaw will be hot.

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   Illustration 17	g06115978

8. Allow the shear to cool before placing back into service. Refer to Operation and Maintenance Manual , "General Guidelines for Build-up and Hard Surfacing" for information on proper cooling.

Blade Pocket Inspect/Repair

Inspect

It is important that the blades fit without excessive clearance within the blade pockets. Excessive clearance can result in premature loosening of the blade bolts.With a high number of high force loads the base material of the pocket can deform and will need to be repaired to maintain the tight fit.

1. Open the jaws of the shear, and place the shear heel on the ground.

2. Turn off the engine and relieve hydraulic pressure.

3. Install the shear rotation lock (if applicable).

4. Apply moving jaw safety rigging. Refer to Operation and Maintenance Manual, "Rigging-Moving jaw safety".

5. With a new blade installed, inspect the clearances of the mating surfaces. The clearance should be no more than 0.2mm.
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   Illustration 18	g06115386
   (A) 0.2mm max

6. If repair is needed, remove the blades and position the shear so that the surfaces that need repair are in a good welding position.

Repair

1. Install the shear rotation lock (if applicable).

2. Clean the area where repair is required.

   Note: If multiple surfaces are in need of repair, it is recommended to work on one surface at a time. Prepare the surface as needed to ensure that a good weld can be applied.

3. Preheat the repair area. Refer to Operation and Maintenance Manual, “General Guidelines for Build-up ...” for information on preheat.
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   NOTICE
   Ground cable should be attached directly to the component being welded. Grounding to other places on the shear could result in arcing through bearing surfaces.This could lead to premature failure of the shear

4. Using AWS A5.18 ER70S weld material, apply small single pass welds with a maximum height of 3mm. Refer to Operation and Maintenance Manual, “General Guidelines for Build-up ” for information on build-up material selection.
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   Illustration 19	g06115388
   (B) Weld

5. Grind the surface smooth ensuring not to grind to the base material.Maintain the surface at the original angle and square with the clamping surface of the pocket. Wear proper eye and hand protection for grinding.
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   Illustration 20	g06115389
   (C) Grind

   Note: Wear proper hand protection as the jaw will be hot. If the blade does not fit, observe the location of the interference and grind this area the appropriate amount to allow a fit.

6. Install a new blade to check fit once the tip is installed, check that the clearance is no more the 0.2mm. If needed repeat from step 4.