Stick Cylinder Seal Kit 087-5407 for CAT 325B Excavator | Hydraulic Repair Set 0875407

Restore Arm Breakout Force & Eliminate Stick Cylinder Drift

Extended excavation, trenching, and heavy load pulling subject the stick (dipper arm) cylinder to continuous bending stress and hydraulic pressure spikes. When internal seals degrade, fluid bypasses the piston head—causing uncommanded stick drift, sluggish arm extension/retraction, reduced crowding force, and external rod gland leaks.

This heavy-duty 087-5407 hydraulic seal kit restores full internal pressure containment and structural holding force for Caterpillar 325B excavators. Precision-molded to match original factory dimensions, every component in this pack ensures a zero-leak, drop-in replacement for field repairs or shop overhauls.

Material & Severe-Duty Engineering

• High-Pressure Rod & Piston Seals: Precision-molded Polyurethane (PU) resists extrusion, dynamic distortion, and sudden hydraulic shock loads up to 35+ MPa.

• Anti-Extrusion PTFE Backing Rings: Reinforced bronze-filled PTFE buffer elements safeguard primary seals against pressure spikes during aggressive arm crowding.

• Thermal-Stable Static Seals & O-Rings: High-durometer Nitrile Rubber (NBR 70°/80° Durometer) maintains constant elastic memory across broad temperature variations while resisting fluid oxidation.

• Heavy-Duty Scraper Wiper: Aggressively repels quartz dust, silica sand, mud, and abrasive slurry from passing the gland seal and scoring the chrome stick rod.

Target Equipment & Component Compatibility

• Machine Model: CAT 325B / 325B L Excavator

• Target Component: Stick (Arm / Dipper) Cylinder Assembly

• Part Number Cross-Reference: 087-5407 / 0875407 / 087 5407

Technical Specifications

• Kit Type: Hydraulic Stick Cylinder Overhaul / Repair Packing Pack

• Primary Materials: Polyurethane (PU), Nitrile Rubber (NBR), Industrial PTFE

• Operating Temperature Range: -30°C to 110°C (-22°F to 230°F)

• Fluid Compatibility: ISO VG 32/46/68 mineral-based hydraulic oils and synthetic fluids

• Installation Target: Direct replacement drop-in fit for job-site service or full cylinder rebuilds

Fitment Verification Notice

Caterpillar 325B excavators feature variations in stick length (e.g., standard vs. long reach) and cylinder barrel sizes depending on serial prefixes. Before placing your order, check the part number stamped on your cylinder head gland or cross-reference 087-5407 / 0875407 in your CAT parts manual to ensure exact dimensional compatibility.