SUPPORT ASSEM. 4J5158 - Caterpillar

Position the fuel tank in order to provide a solid position for the welding operation.
Gouge out all the cracked welds in the fuel tank to a maximum depth of 2 mm (0.07 inch). All the cracked welds must be gouged out to a minimum length of 25 mm (1.0 inch) past the visible ends of the crack. This will ensure that all traces of the cracks are removed.
Grind both parent plates smooth in order to remove any remaining welds.
Personal injury or death can result from an explosion.Applying heat to a tank which has held flammable liquids, even when empty, can result in residual flammable liquid or vapor igniting with explosive force.Do Not weld or flame cut on any tank that has held flammable liquid without taking the proper precautions. Such as; filling the tank with either carbon dioxide or water.Read the article in the Service Magazine July 2,, "Welding On Fuel And Hydraulic Tanks".
All grease, water, paint, rust, dirt, and scale must be removed before welding. Any of these materials will discharge gas which will cause porosity in the weld deposit. Water and rust will cause hydrogen embrittlement. Hydrogen embrittlement causes cracks in the weld deposit.Remove paint, rust, dirt, and scale with a wire brush. Also, remove the defects by buffing the metal plates or by grinding the metal plates. Shot blasting all work areas will also remove foreign material.Remove any oil or grease with a Caterpillar® approved solvent.Weld the fuel tank at the locations that were gouged out. The welds that are deposited must be sufficient to restore the original profile after the welds have been ground smooth.The weld bead should be free of welding spatter or slag.
Grind the weld bead to a smooth finish. Grind the ends of the weld to a smooth finish. Grind the edge of adjacent surfaces in order to eliminate undercut, overlap, protrusions, or any defects. The grinding process will eliminate stress risers that can cause cracks.Manufacturing the Reinforcement Plates
Note: The four reinforcement plates will be manufactured by the Caterpillar dealer.Note: When you fabricate the four plates, use a structural steel with a minimum yield strength of 207 MPa.
Illustration 2 g00899703
Dimensions for Plate 1 (A) 55