1998/01/19 Caterpillar

New U-Cup Seal In Front And Rear Suspension Cylinder Groups Increases Service Life{7201}

Usage:

772 (10S, 11S, 8OS),
772B (64W),
768B (79S),
768C (02X),
776 (14H),
776B (6JC),
776C (2TK),
776D (5ER),
784B (5RK) Off-Highway Tractors;
771C (3BJ),
771D (6JR),
775B (7XJ),
775D (6KR) Quarry Trucks;
769 (99F),
769B (99F),
769C (01X),
769D (5TR),
773 (63G),
773B (5SC, 63W),
773D (7ER),
777 (84A). 777B (4YC),
777C (4XJ),
777D (3PR, 2YW),
785 (8GB),
785B (6HK),
789 (9ZC),
789B (7EK),
793 (3SJ),
793B (1HL),
793C (4AR) Off-Highway Trucks

Reference: Service Magazine; February 13, 1995; "New Suspension Cylinder Rod Seals Reduce Leakage In All Applications" for 784B Tractors, 785, 785B, 789, 789B, 793, 793B Trucks.

Reference: Service Magazine; October 16, 1995; "New Suspension Cylinder Rod Seals Reduce Leakage In All Applications" for 768C, 772B, 776C, 784B Tractors, 769C, 773B, 777C Trucks, 771C, 775B Quarry Trucks.

Reference: Service Magazine; March 21, 1994; "New Suspension Cylinder Rod Seals For Arctic Region Applications" for 768C, 772B Tractors, 769C, 773B Trucks, 771C, 775B Quarry Trucks.

Reference: Service Magazine; February 28, 1994; "Metal-Case Rod Wiper Used In Truck Suspension Groups For Better Retention Of The Wiper Seal" for 768B, 768C, 772, 772B, 776, 776B, 784B Tractors, 769, 769B, 769C, 773, 773B, 777, 777B, 777C, 785, 785B, 793, 793B Trucks, 771C, 775B Quarry Trucks.

Description of Change: A New U-cup seal has replaced the former rod seal and seal (backup ring) in front and rear suspension cylinder groups.

The new U-cup seal withstands extreme temperatures to -60 degrees C (-76 degrees F). A steel spring between the lips of the seal applies a load to the sealing lip, preventing leakage at extreme temperatures.

The new U-cup seal should be used for ambient operating temperature below -20 degrees C (-4 degrees F).

Adaptable To: New 9X-7334, 9X-7364, 9X-7388, 9X-7389, and 9X-7450 U-cup seals, shown in Illustrations 1, 2, and 3, were effective with suspension cylinder groups and models listed in Charts A and B.

New 9X-7334, 9X-7364, 9X-7388, 9X-7389 and 9X-7450 Seals are adaptable to suspension cylinder groups and models listed in Charts C and D.

NOTE: An engineering change number (Eng. Chg.) indicates effectivity of this change or adaptability to earlier cylinder groups. The cylinder group part number, engineering change number, and date of manufacture are found on the cylinder group tag.

Illustration 1.
Typical front suspension cylinder groups, excluding 9T-8910 Front Suspension Cylinder Group. See Illustration 2 for 9T-8910 Front Suspension Cylinder Group.