CAT 472-8018 BEARING-SLV-GD

CAT 472-8018 is a Caterpillar genuine YM type (Y-shaped) hydraulic piston rod/cylinder reciprocating motion seal ring, compatible with Cat 320D/323D excavator main hydraulic cylinders, 950GC loader boom cylinders, 140M grader steering cylinders, etc. It is used to prevent hydraulic oil leakage and external contamination under medium- and high-pressure conditions. Detailed technical and application information is as follows:

Core Technical Parameters
Item Details
Basic Attributes
Model 472-8018, type YM type (Y-shaped) reciprocating motion seal ring (shaft use, double lip structure, with spring accumulator), compatible with Cat 320D/323D excavator main hydraulic cylinders, 950GC loader boom cylinders, 140M grader steering cylinders, material is seal body (polyurethane PU, hardness 90A), spring (stainless steel 304), working pressure 0-32 MPa (short-time peak 40 MPa) Operating pressure: MPa; operating temperature: -30℃ to +100℃; suitable speed: 0.05-0.3 m/s; suitable media: mineral-based hydraulic oil, phosphate ester hydraulic oil (not suitable for water-based hydraulic fluid); unit weight: approximately 0.12 kg; sealing lip contact pressure: ≥1.5 MPa; wear resistance rating: ≥1 million cycles.

Key Dimensions: Inner diameter (shaft diameter compatible): 50 mm (tolerance ±0.10 mm); outer diameter: 65 mm (tolerance ±0.15 mm); thickness: 12 mm (tolerance ±0.08 mm); lip width: 3.5 mm; lip angle: 45°; spring diameter: 0.5 mm; groove dimensions (width 12.5 mm, depth 13 mm, tolerance H7).

Material and Manufacturing Process: The sealing body is made of polyurethane (PU) injection molding, with a smooth, burr-free surface. The lip is polished (roughness Ra≤0.8 μm). The spring is made of stainless steel 304. Winded for rust and corrosion resistance, free from defects such as porosity and cracks. The sealing lip exhibits good elasticity and shows no signs of aging.
Compatible with: Cat 320D/323D excavator main hydraulic cylinders, 950GC loader boom cylinders, 140M grader steering cylinders, and 420F2 loader working device hydraulic systems. Suitable for reciprocating hydraulic cylinder operation, ensuring a seal to prevent hydraulic oil leakage and the entry of external dust and moisture into the cylinder.
Assembly and Fit: Installed in the groove at the front end of the cylinder barrel, fitting snugly against the piston rod surface. The fit clearance is 0.1-0.2 mm. Special tools are required during installation to avoid damaging the lip. A pressure test is required after assembly (25 MPa pressure holding for 5 minutes with no leakage).
Installation and Maintenance: Before installation, clean the cylinder grooves and piston rod surface. Check for deformation of the sealing ring, damage to the lip, and absence of iron filings, oil stains, or other impurities in the grooves. The piston rod surface roughness Ra≤0.8 μm, free from scratches and dents.

During assembly, use a dedicated installation sleeve to press the sealing ring into the groove, ensuring the lip faces the pressure side (hydraulic oil side), the spring does not fall off, and the sealing ring fits tightly into the groove, avoiding twisting or flipping.

Maintenance Recommendations: Check the sealing condition of the sealing ring every 2000 hours. If leakage, lip wear, or hardening occurs, replace the sealing ring immediately. When replacing, simultaneously check the piston rod surface and groove condition, repairing or replacing as necessary.