Mercury Quicksilver Remote Oil Filter Adapter Kit 818400A1

Mercury Quicksilver Remote Oil Filter Adapter Kit 818400A1

Genuine Mercury Marine OEM adapter kit for selected MerCruiser gasoline engines equipped with a remote-mounted oil filter. The adapter mounts at the engine oil-filter location and connects the remote-filter hoses to the lubrication circuit when the engine diagram and hose routing match.

Compatible Applications

• Selected MerCruiser 350 MAG MPI and Horizon engines
• Selected MX 6.2L MPI engines
• Selected Scorpion 377 engines
• Selected 5.7L / 350 V8 applications
• Selected 7.4L / 454 V8 applications
• Selected 8.2L / 502 V8 applications
• Additional sterndrive and inboard engines using the applicable remote oil-filter system

Fitment is engine- and routing-specific. On some 5.7L assemblies, 818400A1 is used where the remote-oil hose enters from the bottom, while another adapter is used for side-entry routing. Confirm the engine serial number and remote-oil-filter diagram before ordering.

Part Details

• OEM part number: 818400A1
• Full service number: 35-818400A1
• Brand: Mercury Quicksilver
• Product type: Remote oil filter adapter kit
• System: Engine lubrication and remote oil filter
• Kit contents: Adapter with one fitting
• Supersedes: 818400T, 860451T, and 807080T
• Quantity: One kit

Key Features

• Genuine Mercury Marine OEM adapter
• Connects the remote oil-filter hoses to the engine lubrication circuit
• Designed for the specified engine oil-filter mounting location
• Fitment depends on engine serial number, hose-entry position, and diagram

Replacement Guidance

Replace the adapter if it is cracked, damaged, leaking at the hose fittings, or if its sealing surface is no longer serviceable. Inspect the seal, gasket, fitting, and remote oil hoses whenever the system is opened.

Installation Notes

Use the applicable MerCruiser service procedure. Related service parts may include adapter seal 42077, fitting 806121, adapter gasket 8M0188440, and remote oil hoses specific to the engine configuration. Verify oil pressure and leak-free operation after installation.

Technical FAQ

Does 818400A1 fit every MerCruiser remote oil-filter system?
No. MerCruiser used more than one adapter and hose-routing arrangement. Match the engine serial number, oil-filter diagram, and hose-entry position before ordering.

What is important about the hose-entry position?
On some 5.7L assemblies, 818400A1 is the adapter for bottom-entry remote-oil hoses. Side-entry assemblies may use a different adapter.

What earlier numbers are replaced by 818400A1?
The listed superseded numbers are 818400T, 860451T, and 807080T. Confirm the current number against the engine diagram before ordering.

Does the kit include the remote oil hoses?
No. The kit includes the adapter and one fitting. Hoses and sealing components are specific to the engine configuration and may need to be ordered separately.

Related Parts

• Mercury MerCruiser Oil Adaptor Seal 26-42077
• Mercury Quicksilver 8M0188440 Oil Filter Adapter Gasket
• Fitting 806121
• Remote oil hoses 860207A1 and 860208 where specified by the engine diagram

Parts Desk Insights

Best use: Use 818400A1 when the applicable MerCruiser engine diagram specifies this remote oil-filter adapter and the hose-entry position matches.

Most common mistake: Choosing the adapter by appearance alone. Bottom-entry and side-entry hose arrangements can use different adapters even on similar engines.

Fitment and sizing: Match the complete 35-818400A1 service number, engine serial number, remote-oil-filter diagram, hose-entry position, and required seal or gasket before ordering.