2812321 Seal Kit Fits Caterpillar Models

One New Aftermarket Replacement Boom Cylinder Seal Kit for Caterpillar (Cat) Mini Excavators

This aftermarket replacement boom cylinder seal kit restores hydraulic cylinder sealing performance on Caterpillar (Cat) mini excavators. The kit services the boom hydraulic cylinder and includes wiper seals, U-cup rod seals, and piston seals. Replaces OEM part number 2812321 (also formatted as 281-2321).

Specifications

• Rod Diameter: 50 mm
• Bore Diameter: 85 mm
• Kit Contents: Wiper seal, U-cup rod seal, piston seal

Compatible Models

Caterpillar Mini Excavators:

• 303.5C CR — Boom Cylinder #2737030 (all s/n), Boom Cylinder #2843369 (s/n DMY1-UP)
• 304D CR — Boom Cylinder #2737031 (s/n TSR1-UP)
• 304E — Boom Cylinder #2737031 (s/n SSC1-UP; TTN1-UP), Boom Cylinder #2843369 (s/n SSC1-UP; TTN1-UP)
• 304E2 CR — Boom Cylinder #2737031 (s/n HC51-UP; KC41-UP), Boom Cylinder #2843369 (s/n FC21-117; GC51-UP), Boom Cylinder #5023494 (s/n FC2118-UP; GC51-UP)

Note: Serial number restrictions apply. Confirm your machine serial number and boom cylinder number before ordering.

Replaces Part Number(s):

2812321, 281-2321

Aftermarket Interchange Numbers

CA2812321, MSS341613BO, CTC-2812321

New aftermarket replacement part – not remanufactured, not used.