- Excavator
- All
- Wheel Loader
- All
Introduction
Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.
While buckets are being loaded, the base edge assemblies will bend or bow and high stresses are developed in the adapter weld. The most severe stresses are concentrated at the start of the welds on the two strap adapters. The points of stress are at the front of the base edge where the welds begin. Consequently, the application of the welds in these areas must be of the highest quality.
Weld quality is improved with the cleanliness of the metal surfaces. Surfaces must be free of paint, rust, dirt, and moisture. There must be good weld penetration into the adapter and the base edge. Weld quality is also determined by:
- the good fusion between weld passes
- application of multiple weld passes
- the absence of abrupt starts of the weld
The metallurgical composition of the base edge and the adapters requires preheating.
The use of low hydrogen welding electrodes or welding wire is required to prevent the formation of hydrogen in the weld. Trapped hydrogen can cause cracks to develop in the weld area.
Preheating and slow cooling also allows any trapped hydrogen to escape. This action prevents excessive hardness from developing in areas that are near the weld. This action also reduces stresses that can occur from rapid cooling and weld shrinkage.
Use the following recommended procedure for welding on all adapters for buckets to achieve maximum durability.
Safety Section
Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility. |
Failure to follow all safety guidelines prescribed in this document and by governing authorities and regulatory agencies may result in severe injury or death of personnel or machine damage. |
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. |
Personal injury or death can result from improper maintenance procedures. To avoid injury or death, follow the procedures exactly as stated below. |
Personal injury can result from improper handling of chemicals. Make sure you use all the necessary protective equipment required to do the job. Make sure that you read and understand all directions and hazards described on the labels and material safety data sheet of any chemical that is used. Observe all safety precautions recommended by the chemical manufacturer for handling, storage, and disposal of chemicals. |
Climbing equipment may be required to access this service point. Refer to the Operation and Maintenance Manual, "Mounting and Dismounting" topic for safety information. |
Before servicing/performing maintenance on the machine, electrical power must be physically disconnected; battery plugs must be disconnected from the batteries, or the trailing cable must be unplugged, and warning tags and padlocks shall be applied by a certified electrician. Certified electricians shall perform or direct any electrical work, including any energized testing, repair work in controllers, motors, or other approved compartments, and shall insure that all compartments are properly closed and inspected prior to re-energization. All applicable lock out and tag out procedures must be followed. |
Do not operate the machine if any guards or covers are missing or inadequately secured. Personnel could be seriously injured or machine damage may occur. |
Observe the safe working load limits of all lifting and blocking devices and keep a safe distance from suspended/blocked loads. Personnel may be seriously injured or killed by falling loads. |
Welding Material
Use a flux cored wire such as AWS E71T-1, which is suitable for use in all positions, with hydrogen control and a gas shielding. Use a wire with a diameter of
Note: If the welds can be applied in a flat horizontal position, you can use an AWS E70T-5 welding wire.
The wires should have a diffusible hydrogen specification of no more than 5 mL per 100 g of weld deposit. Suppliers have different recommendations for the shielding gas. Generally, the use of pure carbon dioxide is acceptable for most choices of welding wire. However, while pure carbon dioxide improves weld penetration, a mixture of 75 percent argon and 25 percent carbon dioxide is recommended for out-of-position welding. The mixture of argon and carbon dioxide also provides the following benefits: enhanced arc characteristics, less welding spatter, and improved bead wetting.
You may use the following low hydrogen stick electrode for all welding: AWS E7018. Since the coating of flux on the stick electrodes will absorb moisture, the coating must be kept dry. Recondition exposed electrodes by heating for 2 hours at a temperature of
Suppliers of welding wire and electrodes make recommendations about power settings. When possible, use DC reverse polarity to obtain the deepest weld penetration. This setting is called "electrode +".
Preparation for Welding
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. Read and understand the manufacturer's instruction and your employer's safety practices. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area. Wear correct eye, ear and body protection. Do not touch live electric parts. Refer to the 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. |
Read the instructions from the supplier and understand the instructions from the supplier. Provide fresh air circulation to the welding helmet to avoid any illnesses that can be caused by long-term exposure to the welding fumes. The fresh air circulation will also remove any exhaled carbon dioxide that may be trapped by the welding helmet. Use the following protection when you prepare the surfaces and when you weld on the surfaces: eye protection, ear protection, and body protection. Use a welding helmet with a filter plate that is at least Shade-11. Welding helmets that automatically darken eliminate strain in the neck by eliminating the need to flip the welding helmet to weld. Also, Welding helmets that automatically darken greatly increase the accuracy in the placement of the electrode.
Before you cut on the bucket or on the weld of the bucket, the temperature of the bucket should be at least
An oxyacetylene torch or an air carbon arc torch may be used to cut an adapter away from the base edge. The air carbon arc torch creates less heat input. This action reduces the tendency for any cracks that may be in the base edge to propagate. The gouged area is also much cleaner after using an air carbon arc torch. This process requires less grinding.
Adapter Removal, Base Edge Preparation, and Sidebar Preparation
All Center and Corner Adapters
- Remove the old adapters. If using air arc gouging or oxyacetylene preheat the weld joint to temperatures between
150° C (302° F) and220° C (428° F) . If grinding, no preheat required. - After removing the old adapters, grind the surface areas that were gouged by the torch.
Corner Adapters Welded Under Sidebar
Illustration 1 | g06281447 |
Grinding bevels to side bar (A) 45° |
- After removal of the corner adapter, grind 45° bevels (A) to the bottom of the side bar. Refer to Illustration 1.
Corner Adapters Welded to Inside Sidebar
Note: This section is optional depending on the condition of the bucket after corner adapter removal
- If bucket sidebar is excessively worn, damaged, or converting from a welded under sidebar configuration, a filler plate will be needed. Refer to Special Instruction, REHS7099, "Rework Procedures for the Excavator D and E-Series Buckets" for a listing of available filler plates or proceed to Step 2 if fabricating from plate steel.
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Illustration 3 g06281491 - Place a new Cat® Advansys half top strap adapter on the base edge and against the inside sidebar. Refer to Illustration 3.
- Mark outline (HH) on the sidebar that will represent the shape of a filler plate. Start approximately half way between the top of the corner adapter and the bottom protector pin hole or sidecutter bolt holes.
- Remove the corner adapter and make a template of the new filler plate shape.
- Cut away the sidebars at outline (HH). If using air arc gouging or oxyacetylene preheat the weld joints and sidebars to temperatures between
150° C (302° F) and220° C (428° F) . If grinding, no preheat required. - Verify that the template matches the newly cut surfaces of the sidebars.
- Using the template, cut out two plates from T-1 or harder steel with the same thickness of the existing sidebars.
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Illustration 4 g06281500 45° both sides - Bevel the bottom of the sidebars and the bottom of the filler plates as shown in Illustration 4.
- Cut bevels equal to approximately half the side bar thickness at the place that the side bar will be welded to the filler plate as shown in Illustration 4. When the side bars are
50 mm (1.97 inch) thick or thicker, make the bevels20 mm (0.78 inch) by 45°. - Cut bevels equal to approximately half the filler plate thickness at the place that the filler plate will be welded to the base edge as shown in Illustration 4. When the filler plates are
50 mm (1.97 inch) thick or thicker, make the bevels20 mm (0.78 inch) by 45°. - Disc grind all surfaces to be welded.
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Illustration 5 g06281509 - Position the filler plates between the sidebars and base edge and check for proper fit up. Apply alternating bevel welds at (AA) and (BB) as shown in Illustration 5 until completed.
- Apply a bevel weld at (CC) between the base edge and filler plate as shown in Illustration 5.
Illustration 2 | g06281463 |
Corner adapter with a half top strap for welding to inside sidebar |
Two Strap Center Adapters with a Continuous Rear Weld Groove
Note: This section is for adapters with a single continuous weld groove for each strap, covering both sides and the rear potion of the strap.
- Assemble the adapter bevel (L) with hard contact against the base edge bevel (K), while equalizing the gaps of the adapter straps. The minimum gap requiring equalization is
3 mm (0.12 inch) and must be equalized within ±3 mm (0.12 inch) to the base edge (J). Use soft wire spacers to hold the position while tack welding at mid length in the root of the weld groove on each side of the strap. - IMPORTANT: Preheat the adapter and the edge to a minimum
150° C (302° F) . The maximum welding interpass temperature is260° C (500° F) . Monitor temperatures frequently to ensure that these thresholds are not exceeded during the entire welding process.Note: All weld start points, stop points and weld illustrations are general and should be considered equivalent for both the top and bottom straps.
- Begin the first weld bead at the front of the top strap weld groove root at point (A) or point (E) as shown in Illustration 6. Weld one continuous pass to the beginning of the rear adapter arc at point (B) or (F) or you can continue welding around the rear adapter arc (C) to (D) as shown in Illustration 7. Stagger all weld stops and starts as shown in Illustration 8. Weld stops and starts are not recommended from (C) to (D).
- Move to the other side of the adapter and begin the next weld bead at the front of the top strap weld groove root at point (A) or point (E) as shown in Illustration 6. Weld one continuous pass to the beginning of the rear adapter arc at point (B) or (F) or you can continue welding around the rear adapter arc (C) to (D). Stagger all of the weld stops and starts as shown in Illustration 8. Weld stops and starts are not recommended from point (C) to point (D).
- Return to the original welded side and weld the next pass.
- Continue welding alternative sides of the top strap until the weld groove from point (A) to point (E) is filled. Do not apply fillet welds at this time.
- If welding multiple center adapters to a bucket, repeat Steps 1 through 6 for all.
- Turn the base edge (J) over such that the bottom side is facing up. Repeat the procedures in Steps 2 through 6 for all bottom straps.
- After all weld grooves are filled on both the top and bottom straps, fillet welding may begin. Start the first fillet weld pass at point (A) or point (E). All succeeding weld beads should start behind the preceding layer to produce a staggered weld start end as shown in Illustration 8. The fillet bead passes should be applied alternately on each side of the strap from front to back as described in Steps 3 and 4. The final weld pass should be on the previously deposited weld near, but not on the base edge (J) weld toe.
- If welding multiple center adapters to a bucket, weld all bottom straps per Step 9.
- If necessary, grind to blend the starts or stops of the weld and weld toe undercuts. After the initial pass, all weld stops must tie into the previously applied weld ends.
- Turn the base edge (J) over such that the top side is facing up. Perform fillet welding and blending for all top straps per Steps 9 and 10.
- Allow all finished welds to slow cool.
Illustration 6 | g06281514 |
Top view of base edge and adapter (A) Point A (B) Point B (E) Point E (F) Point F |
Illustration 7 | g06281517 |
Top view of base edge and adapter (C) Point C (D) Point D |
Illustration 8 | g06281524 |
(G) Adapter
(H) Adapter to base edge weld (J) Base edge (K) Base edge Bevel (L) Adapter bevel (N) First weld pass (P) Second weld pass (R) Third weld pass (S) Fourth weld pass (T) Fifth weld pass (U) Final weld pass (AA) |
Two Strap Center Adapters with Side Only Weld Grooves
Note: This section is for adapters with two weld grooves for each strap, covering only the strap sides. There is not a weld groove on the rear portion of the strap.
- Assemble the adapter onto the base edge and preheat as detailed in Steps 1 and 2 from "Two Strap Center Adapters with a Continuous Rear Weld Groove".
- Begin the first weld bead at front of top strap weld groove root at point (B) or (G) as shown in Illustration 9. Apply continuous weld pass to point (C) or (H) respectively.
- Move to the other side of the adapter and repeat Step 2. Fill both weld grooves with alternating weld passes.
- If welding multiple center adapters to a bucket, repeat Steps 1 through 3 for all.
- Turn the base edge over such that the bottom side is facing up. Repeat the procedures in Steps 2 and 3 for all the bottom straps.
- After all weld grooves are filled on both the top and bottom straps, fillet welding may begin. Start the first fillet weld pass at point (A) or point (F). All succeeding weld beads should start behind the preceding layer to produce a staggered weld start end as shown in Illustration 8. Continue welds
25 mm (0.98 inch) to50 mm (1.97 inch) past the rear of the adapter to (point (D) or (K)) while tapering it down to a height of3 mm (0.12 inch) at the end. The fillet weld bead passes should be applied alternately on each side of the strap from front to back as described in Steps 2 and 3. The final weld pass should be on the previously deposited weld that is near, but not on the weld toe of the base edge. - Finish the tail welds. Begin next weld bead at the rear of the adapter (Point (E) or (J)) and weld one continuous pass
25 mm (0.98 inch) to50 mm (1.97 inch) beyond the rear of the Adapter (point (D) or (K)) while tapering it down to a height of3 mm (0.12 inch) at the end. The same number of fillet welds should be applied to each side of the tail as per Step 6. - Move to the other side of the adapter and repeat Step 6 for the second tail.
- If welding multiple center adapters to a bucket, weld all straps per Steps 6 through 8.
- If necessary, grind to blend the starts or stops of the weld and weld toe undercuts. After the initial pass, all weld stops must tie into the previously applied weld ends.
- Turn the base edge over such that the top side is facing up. Perform fillet welding and blending for all top straps per Steps 6 through 10.
- Allow finished welds to slow cool.
Illustration 9 | g06281534 |
Top view of base edge and adapter |
Two Strap Corner Adapters Positioned Under Sidebar
- Assemble the adapter onto the base edge and preheat as detailed in Steps 1 and 2 from "Two Strap Center Adapters with a Continuous Rear Weld Groove".
Note: All weld start points, stop points and weld illustrations are general and should be considered equivalent for both the top and bottom straps.
- Begin the first weld bead at front start of top strap weld groove root (JJ) or (MM). Illustration 10 details groove locations, not the starting points. Apply continuous weld pass to end of groove (side only weld groove adapter) or till weld groove reaches sidebar (continuous rear weld groove adapter).
- Move to the other side of the adapter and repeat Step 2. Fill both weld grooves with alternating weld passes. Do not start fillet welds.
- Apply weld between adapter top and sidebar, alternating passes from sides (KK) and (LL) until the weld bevel is filled. Do not have any starts or stops within section (NN) or near the corner transitions to (KK) and (LL). Do not start fillet welds.
- If welding multiple corner adapters to a bucket, repeat Steps 1 through 4 for second adapter.
- Turn the bucket over such that the bottom side is facing up. Weld the corner adapter bottom straps using the same methods for welding the center adapter bottom straps. There are two options depending on the adapters weld groove geometry:
- a) if applicable, Refer to "Two Strap Center Adapters with a Continuous Rear Weld Groove", Steps 8 through 11.
- b) if applicable, Refer to "Two Strap Center Adapters with Side Only Weld Grooves", Steps 5 through 10.
- Turn the bucket over such that the top side is facing up.
- Apply the fillet welding between the adapter and the top of the base edge covering groove welds (JJ) and (MM). All succeeding weld beads should start behind the preceding layer to produce a staggered weld start end as shown in Illustration 8. The fillet bead passes should be applied alternately on each side of the strap from front to back. The final weld pass should be on the previously deposited weld near, but not on the base edge weld toe.
- Apply the fillet welds between the adapter top and the sidebar covering groove welds (KK), (LL), and (NN). Alternate weld passes from sides (KK)) and (LL). Do not have any starts or stops within section (NN) or near the corner transitions to (KK)) and (LL). Blending welds with sidebar weld (CC).
- If welding multiple corner adapters to a bucket, repeat Steps 8 and 9 for second adapter.
- If necessary, grind to blend the starts or stops of the weld and weld toe undercuts. After the initial pass, all weld stops must tie into the previously applied weld ends. The transition from the leading edge of the sidebar to the adapter top, should be ground smooth to eliminate any stress concentrating ridges or undercutting.
- Allow finished welds to slow cool.
Illustration 10 | g06281565 |
Two Strap Corner Adapters with Half Top Strap Positioned to Inside Sidebar
- Assemble the adapter with hard contact at the base edge bevel (groove (HH)) and between adapter top strap and side bar at weld groove (FF). Equalize the top and bottom base edge gaps of the adapter straps. The minimum gap requiring equalization is
3 mm (0.12 inch) and must be equalized within ±3 mm (0.12 inch) to the base edge. Use soft wire spacers to hold the position while tack welding at mid length in the root of the weld groove on the top strap. - IMPORTANT: Preheat the adapter, edge, and sidebar to a minimum
150° C (302° F) . The maximum welding interpass temperature is260° C (500° F) . Please monitor temperatures frequently to ensure that these thresholds are not exceeded during the entire welding process.Note: All weld start points, stop points and weld illustrations are general and should be considered equivalent for both the top and bottom straps.
- Begin the first weld bead at front start of top strap weld groove root (HH) or (DD). Apply continuous weld pass to end of groove (HH) or till weld groove reaches sidebar (DD).
- Move to the other side of the adapter and repeat Step 2. Fill both weld grooves with alternating weld passes. Do not start fillet welds.
- Fill weld grooves (EE) and (FF) with no starts and stops at the leading-edge transition between the sidebar and top of the adapter.
- If a sidebar filler plate was used, apply a bevel weld (GG) between the base edge and filler plate.
- If welding multiple corner adapters to a bucket, repeat Steps 1 through 6.
- Turn the bucket over such that the bottom side is facing up. Weld the corner adapter bottom straps using the same methods for welding the center adapter bottom straps. There are two options depending on the adapters weld groove geometry:
- a) if applicable, Refer to "Two Strap Center Adapters with a Continuous Rear Weld Groove", Steps 8 through 11.
- b) if applicable, Refer to "Two Strap Center Adapters with Side Only Weld Grooves", Steps 5 through 10.
- Turn the bucket over such that the top side is facing up.
- Apply the fillet welding between the adapter and the top of the base edge covering groove welds (DD) or (HH) and (GG). All succeeding weld beads should start behind the preceding layer to produce a staggered weld start end as shown in Illustration 8. The fillet bead passes should be applied alternately on each side of the adapter from front to back. The final weld pass should be on the previously deposited weld near, but not on the base edge weld toe.
- Apply the fillet welds between the adapter top and the sidebar covering groove welds (EE) and (FF). Do not start or stop a fillet at the leading-edge transition between the sidebar and top of the adapter. Alternate weld passes from side to side, blending welds with sidebar weld (CC) and (GG).
- If welding multiple corner adapters to a bucket, repeat Steps 10 and 11 for second adapter.
- If necessary, grind to blend the starts or stops of the weld and weld toe undercuts. After the initial pass, all weld stops must tie into the previously applied weld ends. The transition from the leading edge of the sidebar to the adapter top, should be ground smooth to eliminate any stress concentrating ridges or undercutting.
- Allow finished welds to slow cool.
Illustration 11 | g06281588 |
Single Strap Center Adapters
- Assemble the adapter bevel (R) with hard contact at the base edge bevel (P). The top strap should be flush to the base edge top surface. Tack weld at mid length in the root of the weld groove on each side of the strap.
- Tack weld a
10 mm (0.40 inch) thick mild steel starter plate to the bottom leading edge of the base edge (M) at the junction of the upper and lower weld grooves. - IMPORTANT: Preheat the adapter and edge to a minimum
150° C (302° F) . The maximum welding interpass temperature is260° C (500° F) . Monitor temperatures frequently to ensure that these thresholds are not exceeded during the entire welding process. - Begin the first weld on the starter plate at the front of the top strap weld groove root at point (B) or point (G). Weld one continuous pass to the rear of the adapter weld groove at point (C) or (H).
- Move to the other side of the adapter and repeat.
- Return to the original welded side and weld the next pass.
- Continue welding alternative sides of the strap until the weld grooves are filled
- Begin the first fillet weld on the starter plate at the front of the weld groove root at point (A) or point (F). Start succeeding weld beads slightly behind the preceding layer to produce a staggered weld start. Weld one continuous pass
25 mm (0.98 inch) to50 mm (1.97 inch) past the rear of the adapter at point (D) or (J), while tapering the weld to3 mm (0.12 inch) at the end. Fillet weld bead passes should also be applied alternately on each side of the strap from front to back. The final weld pass should be on the previously deposited weld near, but not on the base edge weld toe. - Finish the tail welds. Begin the next weld bead at the rear of the adapter at point (K) or (E). Weld one continuous pass
25 mm (0.98 inch) to50 mm (1.97 inch) beyond the rear of the adapter to point (D) or (J). While tapering the weld to3 mm (0.12 inch) at the end. The same number of fillet weld passes should be applied to each side as per Step 8. - Weld all adapter top straps following Steps 1 through 9.
- Turn the base edge (M) over to where the bottom side is facing up. Arc-air gouge through the starter plates until the upper welds are exposed.
- Fill the lower weld groove by starting the welds from alternate ends of the groove. At completion, the lower weld should be flush with the bottom of the base edge (M). This area should also be blended with the ends of the upper welds.
- Weld all bottom grooves as directed in Steps 11 and 12.
- If necessary, grind to blend the starts or stops of the weld and weld toe undercuts. After the initial pass, all weld stops must tie into the previously applied weld ends.
Illustration 12 | g06281617 |
Top view of base edge and adapter (A) Point A (B) Point B (C) Point C (D) Point D (E) Point E (F) Point F (G) Point G (H) Point H (J) Point J |
Illustration 13 | g06281625 |
(L) Adapter
(M) Base edge (N) Adapter to base edge weld (P) Base edge bevel (R) Location adapter bevel, view is blocked by the adapter to base edge weld |
Illustration 14 | g06281634 |
Bottom view of base edge and adapter (S) View of fillet welds |
Reference Section
Reference: Special Instruction, REHS7099, "Rework Procedures for the Excavator D and E-Series Buckets".