SUPPORT AS 4E9976 - Caterpillar

Image1.2.1
Image1.2.2
6. Grind to a depth of 6mm and width of 6mm in order to remove the weld crack. Refer to Image1.3.1.
Image1.3.1
7. Carry out the DP test to ensure the defect is removed. Clean the area with cleaner in order to remove the DP particles whenever the welding is carried out after DP test.
8. Carry out the weld rework in the vertical position (3G position) and ensure that a 45-degree angle is maintained to sidewall fusion. Provide stiffener at open end in order to avoid weld distortion and to ensure the bore inline.
Refer to Image1.4.2.
Image1.4.2
9. Conduct DP Test to ensure a defect free weld after root run.
10. After ensuring a defect free weld in the DP test, complete the welding with a 2nd pass.
11. Grind the welded area smooth and conduct DP Test to ensure a defect free weld.
12. Paint the reworked area and connect the battery earth, if disconnected.
13. Reassemble the boom and reconnect all hydraulic lines that were disconnected.
Refer to Image1.5.1.
Image1.5.1
PROCEDURE FOR FAILURE MODE 2: TOE CRACK ON BOOM TOP AND BOTTOM WELD
1. Complete a visual check for any crack presence on the boom assembly side, near the stick mounting.
2. If the M/C level rework is done, boom removal is not required. Clean the area where the crack is found.
3. Grind the crack area smooth to remove paint for DP test.
Refer to Image1.6.1.
Image1.6.1
4. Conduct DP Test to check the extent of the crack.
5. Mark a point 5mm above the crack initiation point and drill a 4mm diameter hole as shown.
Refer to Image1.7.1 and 1.7.2.
Image1.7.1
Image1.7.2
6. Make chamfer (6mm x 45 Degrees) for welding. Ensure that the crack line is removed by grinding in side and the plate bottom smooth. Ensure the root gap is maintained between 0 to 2mm.
7. Carry out the weld rework in vertical position (3G) and ensure good root fusion.
8. Conduct DP Test to ensure a defect free weld after root run.
9. After ensuring a defect free weld in DP, complete the welding with a 2nd pass.
Refer to Image1.8.1 and 1.8.2.
Image1.8.1
Image1.8.2
10. Grind the welded area smooth and conduct DP Test to ensure a defect free weld.
11. Paint the reworked area and connect the battery earth, if disconnected.
12. After rework, reassemble the boom and connect all hydraulic lines that were disconnected.
Refer to Image1.9.1.
Image1.9.1
PROCEDURE FOR FAILURE MODE 3: BOTTOM NOSE END CRACK
1. Park the machine at convenient location on level ground. Keep the rear Backhoe structure at extended position and keep the Hoe Bucket at rest on the ground.
2. If the boom rework is done with M/C level (optional), remove battery earth connection.
3. Perform visual check for bottom nose end crack.
Refer to Image1.10.1.
Image1.10.1
4. Conduct DP Test to check the extent of crack. Refer the DP test guidelines.
5. Remove the weld thoroughly by grinding.
6. Complete root weld and fill the gap.
7. Ensure the welding holder angle is 45-degrees to ensure the side wall fusion.
8. Grind the weld, if required, and conduct DP Test to ensure a defect free weld.
9. Paint the reworked area and connect the battery earth,