2426840 Hydraulic Cylinder Seal Kit for CAT 325C, 325D L, 329DL, 330C, 330D, 336D Boom Cylinder 2502419

Six CAT models share this boom cylinder seal kit: 325C, 325D L, 329DL, 330C, 330D, and 336D. OEM references 2426840 and 2502419. The boom cylinder carries the whole front end, so its seals live under high pressure and constant shock. When they fail, the boom sags, lift slows, or the rod comes back wet. This kit replaces the rod, piston, and static sealing points.

Seals are PU and NBR. PU handles the pressure lips and sliding wear. NBR covers oil-side and static sealing. Profiles are molded to OEM groove dimensions, so no trimming or stretching. Seal kit only — barrel, rod, and piston are not included.

Check the machine serial and cylinder part number before ordering. These six models can run more than one boom cylinder setup, so the model name alone may not be enough.