REGULATOR AS-VOLTAGE 3987247 - Caterpillar

Illustration 1 g02311375
Left side view of the former plate (B) Width of the plate 8 mm (0.3 inch)
Illustration 2 g02313295
Left side view of an improved plate (C) Width of the plate 10 mm (0.4 inch)An improved 257-8853 Plate As is redesigned to increase the material thickness.An improved 257-8853 Plate As with increased material thickness is adaptable to Off-Highway Trucks that are listed above back to first production and is effective in production with serial numbers that are listed in Table 1.
Table 1
Effective Serial Numbers for an Improved 257-8853 Plate As    
S/N:JRP2229-UP    
S/N:JXP152-UP    If the former 257-8853 Plate As gets cracked, then either replace the former plate assembly with an improved 257-8853 Plate As or follow the proper weld repair procedure mentioned below.Rework Procedure:
Remove 238-1231 Brake Accumulator and Mounting Gp .
Remove 257-8853 Plate As mounting hardware and save the hardware. Remove 257-8853 Plate As .
Remove debris and clean affected area of plate assembly for weld joint preparation.
Illustration 3 g02313375
Cracked plate (D) 110 mm (4.3 inch) minimum. (1) Cracking area
Illustration 4 g02313414
Weld joint preparation (E) 45 degrees (F) 8 mm (0.3 inch) (G) Maximum 8 mm (0.3 inch) root opening (H) 50 mm (2.0 inch) (W1) Weld penetration 1.5 mm (0.06 inch)
Use the steel backup strip (2) with minimum yield strength of 290000 kPa (42062 psi) for weld repair.
Position the backup strip (2) with the 257-8853 Plate As such that back up strip extends a minimum of 12 mm (0.5 inch) equally on both sides beyond the existing plate assembly edges as shown in Illustration 3.
Tack the backup strip (2) at the joints (3) on both sides of the 257-8853 Plate As as shown in Illustration 4.
Weld the entire length of the backup strip (2) with 8 mm (0.3 inch) bevel groove weld and 1.5 mm (0.06 inch) penetration as shown in Illustration 4.
Grind both the edges of the backup strip (2) to match the 257-8853 Plate As contour, once the welding is completed. Grinding the edges of backup strip (2) as per plate assembly contour will prevent the crack initiation in the same location.
Install the welded 257-8853 Plate As with the mounting hardware that were saved in Step 2.
Install 238-1231 Brake Accumulator and Mounting Gp .