Caterpillar 1S-3898 Plunger

Caterpillar 1S-3898 Engine Oil Pump Pressure Relief Plunger is an authentic Cat component designed to regulate and maintain safe, consistent engine oil pressure within CAT lubrication systems, ensuring the oil pump’s relief mechanism responds accurately to changing engine demands. This steel-plunger design resides in the oil pump relief circuit and functions as the adjustable element that helps set the relief pressure, with Cat catalogs listing 1S-3898 specifically as the Engine Oil Pump Pressure Relief Plunger and labeling it as an original Caterpillar part. Retail listings corroborate its OEM status and Caterpillar compatibility, including the Cat Parts Store entry under Engine Lubrication System components and aftermarket references such as the 1S3898 listing on retailers like Walmart.