4L8121 Gasket for Caterpillar Equipment

4L8121 is a flat gasket used in Caterpillar engines, engine and generator assemblies, industrial engines, and ship equipment. This is a new aftermarket spare part manufactured by CTP (Costex Tractor Parts).

The gasket is identified by the part number format 4L8121 and is also referenced as 4L-8121. The available application data covers Caterpillar D-series and G-series engines used in the equipment groups listed below.

Fitment

• Engine and generator kits:
  • Caterpillar D379B
  • Caterpillar D398B
  • Caterpillar D399
• Industrial engines:
  • Caterpillar D379
  • Caterpillar D379B
  • Caterpillar D398
  • Caterpillar D398B
  • Caterpillar D399
  • Caterpillar G379
  • Caterpillar G379A
  • Caterpillar G398
  • Caterpillar G399
• Ship equipment:
  • Caterpillar D379A
  • Caterpillar D379B
  • Caterpillar D398A
  • Caterpillar D398B
  • Caterpillar D399

Fitment is listed by engine and equipment series. The part should be matched with the engine model and the gasket location before installation, since the available data does not specify the exact assembly position.

Cross-reference numbers

• 4L8121 — product SKU and part number format without a hyphen
• 4L-8121 — hyphenated part number format

The listed numbers refer to the same gasket identification. No additional supplier or equipment-manufacturer cross-reference numbers are provided in the available product data.

Specifications