Description

The Mercury Quicksilver Adaptor Sealing O-Ring 25-33756 is an OEM-style sealing ring used between the oil filter and filter valve/adaptor on select Mercury and MerCruiser engine applications. It helps keep pressurized engine oil sealed at the adaptor base and prevents leaks around the filter mounting area.

Key Features

• Genuine Mercury/Quicksilver sealing O-ring
• Part number: 25-33756
• Also referenced as 33756
• Oil filter adaptor / filter valve sealing ring
• Designed for engine oil sealing applications
• GTIN / UPC: 0745061136847
• Helps prevent oil seepage at the filter adaptor connection

Engine Compatibility

Used on select Mercury and MerCruiser engine applications where this O-ring is shown in the oil filter, filter valve, or adaptor parts diagram.

Serial Number Fitment Notice

Verify fitment by engine serial number and oil filter adaptor diagram before ordering. O-ring size and material can vary by engine block, filter adaptor style, and production range.

When This Part Needs Replacement

Replace this O-ring if oil is leaking around the filter adaptor, if the seal is flattened, cracked, swollen, hardened, cut, or removed during oil filter adaptor service.

Installation Notes

Clean the sealing groove and mating surfaces before installation. Lightly lubricate the O-ring with clean engine oil before assembly, and make sure it seats evenly without twisting or pinching.

Alternate/Superseded Part Numbers

Primary Mercury references: 25-33756 and 33756. Common aftermarket interchange: GLM Marine 42400.

Parts Desk Insight

Small oil-system O-rings can cause messy leaks when reused or pinched. Replacing the seal during adaptor service is a simple way to prevent repeat oil seepage.

Shipping: Ships same or next day for fast Canada wide shipping.