Sierra O-Ring 18-7459 for Mercury Outboard Powerhead, Replaces 20311, 25-20826

The Sierra O-Ring 18-7459 is a powerhead seal designed for Mercury outboard applications, engineered to maintain a reliable seal at critical mating surfaces and prevent leaks that can lead to water intrusion, oil loss, or pressure loss within the powerhead. As a direct aftermarket replacement, it is manufactured to match the fit and function of the original equipment it replaces, giving boat owners and marine technicians a dependable option when servicing Mercury outboard powerheads. This O-ring cross-references Mercury Marine part numbers 20311 and 25-20826, so it can be ordered with confidence when either of those numbers appears on a parts diagram or in a service manual. It ships as a single unit (package quantity of one), sized for the specific application it serves rather than as a bulk assortment. Compact and lightweight at 0.01 pounds with overall dimensions of 0.39 x 0.39 x 0.39 inches, the 18-7459 O-ring is easy to keep on hand as part of a seal kit or standalone replacement stock for routine powerhead maintenance, gasket replacement jobs, or teardown and rebuild work. Because it is sold under the Sierra part number 18-7459, technicians can standardize on a single, consistently cataloged part number rather than searching multiple OEM cross-references each time a replacement is needed.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7459
• Category: Mercury Outboard Powerhead Seals & O-Rings
• Package Quantity: 1
• Weight: 0.01 pounds
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• UPC: 030999876300
• Replaces (OEM): 20311, 25-20826

Fitment

Intended for Mercury outboard powerhead applications.

Replaces (OEM)

• 20311
• 25-20826

Frequently Asked Questions

What does the Sierra 18-7459 O-ring replace? The Sierra 18-7459 O-ring cross-references OEM Mercury Marine part numbers 20311 and 25-20826, making it a direct replacement for either of those part numbers.

What is the Sierra 18-7459 O-ring used for? This O-ring is used as a seal in Mercury outboard powerhead applications, part of Sierra's Mercury Outboard Powerhead Seals & O-Rings category.

How much does the 18-7459 O-ring weigh? The Sierra 18-7459 O-ring weighs 0.01 pounds.

What are the dimensions of the 18-7459 O-ring? The 18-7459 O-ring measures 0.39 x 0.39 x 0.39 inches.

How many O-rings come in a package of Sierra 18-7459? Sierra part 18-7459 is packaged as a single O-ring, with a package quantity of 1.

Is the Sierra 18-7459 an OEM or aftermarket part? The 18-7459 is a Sierra-brand aftermarket O-ring manufactured to replace OEM Mercury Marine numbers 20311 and 25-20826.

What is the UPC for the Sierra 18-7459 O-ring? The UPC for the Sierra 18-7459 O-ring is 030999876300.

Does the 18-7459 O-ring fit Mercury outboards specifically? Yes, the 18-7459 is categorized by Sierra for Mercury outboard powerhead applications.

Can I use OEM number 25-20826 to find the correct replacement O-ring? Yes, part number 25-20826 cross-references directly to the Sierra 18-7459 O-ring.

What brand makes part number 18-7459? Part number 18-7459 is manufactured by Sierra.