8C9138 Buffer Seal for Caterpillar Equipment

The 8C9138 Buffer Seal is a Type B seal used in hydraulic and mechanical assemblies of Caterpillar off-highway trucks and backhoe loaders. It is a new aftermarket spare part manufactured by CTP (Costex Tractor Parts).

The part is identified by SKU 8C9138 and is also listed in the hyphenated part-number format 8C-9138. The Caterpillar designation refers to the equipment manufacturer whose machines are listed for this seal.

Fitment

The 8C9138 Buffer Seal is listed for the following Caterpillar equipment models:

• Off-highway truck: Caterpillar 768C
• Off-highway truck: Caterpillar 769C
• Off-highway truck: Caterpillar 771C
• Backhoe loader: Caterpillar 428B
• Backhoe loader: Caterpillar 438B

Fitment is specified by the machine model series above. The available part data does not identify a particular installation position, cylinder assembly, or machine serial-number range.

Cross-reference numbers

• 8C-9138

8C-9138 is the hyphenated number format associated with SKU 8C9138. No additional supplier numbers are provided in the available product data.

Specifications

The dimensional values above are stated in the available specification data. Groove width A and groove diameter H are given with a tolerance of 0.005 in. The listed weight and centimetre dimensions are recorded separately from the seal-form and groove measurements; the available data does not specify whether they represent the part or its packing.

Before installation, verify the machine model, the existing seal number, and the required groove and stem dimensions against the equipment service documentation. The available description does not state the seal material, operating-temperature range, pressure rating, installation kit contents, or quantity supplied.