Caterpillar 5H-4081 Seal O Ring

Caterpillar 5H-4081 Seal O Ring is a genuine Cat OEM nitrile Buna (NBR) O-ring, sized with a 5.33 mm cross-section and an inner diameter of 221.62 mm (75A hardness), designed specifically as the left-hand side parking brake seal to provide fluid-tight connections and prevent leaks in hydrostatic-drive parking brake assemblies. Made from NBR for compatibility with hydraulic fluids used in Caterpillar equipment, this O-ring delivers reliable sealing performance across standard service temperatures and pressures typical of CAT parking brake housings. The 5H-4081 seal is chosen where a large-diameter, high-hardness O-ring is required to maintain brake integrity and prevent fluid loss in hydraulic systems, aligning with Caterpillar's OE specifications for sealing interfaces in parking brake components. Use this CAT part within its intended hydraulic sealing applications and verify fitment via the machine's service manual or CAT parts diagrams.