SUPPORT AS 3734079 - Caterpillar

Cutting Requirements
Removal of the components is to be accomplished using air arc (CAC-A) gouging. Safe practices must be followed which include AWS C5.3-8.2: “Recommended Practices for Air Carbon Arc Gouging” and ANSI Z49.1 “Safety in Welding and Cutting”.Repair Procedure
Illustration 1 g06067759
(A) Crack at top portion of lift arm assembly
Illustration 2 g06067768
(B) Crack at bottom portion of box section
Illustration 3 g06067772
(C) Crack extends over the parent material
Inspect the areas shown, and see if a crack exists.
If a crack was found, remove the lift arm from the machine for weld rework.
Perform any welding in the 1G / 1F or 2G / 2F position. It is important that the welder performing the rework must be qualified in the afore mentioned positions as outlined in the current ANSI/AWS standards.
Clean the cracked or damaged weld area to ensure that the crack is free from oil, paints, grease, and rust.
Keep the plate surfaces and welding rods dry to help prevent the welds from cracking.
Illustration 4 g06067838
Pencil type grinding machine
Use a pencil type grinder as shown in Illustration 4 to clean the welds.
Conduct a Dye Penetrant (DP) to ascertain the extent of the weld defect and precisely to find out the edges of the crack.Note: All slag or foreign material must be removed from the crack before checking dye penetrant.
Remove the cracked region by gouging / grinding and check with dye penetrant to ensure that the crack was removed.
Ensure that the slag and other by products from the removal process do not cover up the defective weld before checking with dye penetrant.
Ensure that the entire defective weld has been removed down to solid material by using dye penetrant.
Extend the weld metal removal beyond the defect / crack a minimum 25.0 mm (0.98 inch) to 50.0 mm (1.97 inch)
Keep the rework surface free from moisture and dust.
Completely remove defects to sound metal prior to welding. Taper the ends of the gouged area to provide a smooth transition to the base metal.
To arrest further crack in the area, drill to a diameter of 3.0 mm (0.12 inch) or 4.0 mm (0.16 inch) with hand drill at either end (tip) of the crack or if drilling is not possible punching can be done as an alternate process.
Base metal crack needs to be reworked before reworking the weld metal crack.
Make a 5.0 mm (0.20 inch) x 45 degree “V” groove by grinding.
Fill the “V” groove with weld metal and ensure that the drilled hole is plugged by welding.
Use suitable grinding/finishing equipment to smooth the surface of the built up area to the original profile (matching with the adjacent area).
Perform a visual weld defect inspection. If any defects are noticed grind the defective location and reweld.
Check that the reworked area is free from external defects. Check with DP to ensure defect-free welding.
After completing the base metal crack, reweld the damaged fillet weld as per drawing requirement.
Use suitable grinding/finishing equipment to smooth the surface of the built up area to the original profile (matching with the adjacent area).
Perform a visual weld defect inspection. If any