2002/11/04 Caterpillar

Off-Highway Truck:

797 (S/N: 5YW1-UP)

Service Magazine, SEPD0576, 30 April 2001, "Improved Components Are Available For The Hoist Cylinders On 797 Off-Highway Trucks". The information in the article has been updated. Replace the article with the following information.

Description of Change: New backup rings, a new seal, and a new piston are available for 150-3008 Hoist Cylinder Gp. The new components will provide improved service life.

Adaptable To: The new components are effective with 797 (S/N: 5YW241) and adaptable to 797 (S/N: 5YW1-240). Refer to Table 1 and Illustration 1 for a list of available part numbers. Use the following procedure to rework 150-3012 Piston.

Table 1

Item	New Part Number	Description	Former Part Number
1	199-1476 (1)	Backup Ring	150-3425
2	199-1474	Backup Ring	150-3418
3	199-1475	Backup Ring	150-3420
4	199-1477	Backup Ring	150-3424
5	199-0962	Seal	150-3414
6	199-0908	Piston	150-3012

( 1 )

The 199-1476 Backup Ring is part of the 150-3013 Cylinder .

Illustration 1	g00792238
This is a view of the 150-3008 Hoist Cylinder Gp .

Show/hide table



Illustration 2	g00919706

1. Measure the width (A) of the seal groove in the piston. The specified dimension for the width of the groove is 11.18 ± 0.01 mm (0.4402 ± 0.0004 inch).

2. Machine an equal amount of material from both sides of the seal groove in order to make the width of the groove 17.53 ± 0.010 mm (0.6902 ± 0.0004 inch). The depth of the groove must be maintained when the groove is widened.

   Note: There should be no steps in the bottom of the groove.

3. Stamp an "X" after the part number on the piston when the rework has been completed. The new part number must appear as "150-3012X".