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Sierra 18-1827 Water Pump Housing Grommet for Johnson/Evinrude Outboards

Manufacturer

Sierra

<h3>Sierra: Six Decades of Marine Aftermarket Excellence</h3><p><strong>Sierra</strong> has spent nearly 60 years earning its reputation as one of the most trusted names in the marine aftermarket industry. Originally focused on engine and drive components for boats, the brand has grown into a comprehensive source for nearly everything a boater needs to keep their vessel running at its best — from precision instrumentation to complete engine rebuild hardware.</p><p>Now operating as a brand of Dometic, Sierra manages global aftermarket distribution from a 300,000 sq. ft. facility in Litchfield, Illinois. The Sierra brand today encompasses not only its flagship marine parts line but also well-established marine names like Shields and Moeller, offering boaters a broader catalog than ever before. Whether you own an outboard, inboard, or sterndrive, Sierra's engineering team designs products to meet or exceed OEM specifications.</p><h3>Precision Instrumentation You Can Trust on the Water</h3><p>One of Sierra's most recognized product areas is its marine instrumentation lineup. The brand's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> cover everything from classic analog instrument clusters to advanced digital multi-function displays. Sierra offers packages suited to outboards, sterndrives, and gasoline-powered inboards, with options ranging from coordinated analog kits in styles like Arctic, Eclipse, and Amega to modern touchscreen solutions like the R3 multi-function gauge. Features such as scratch-resistant domed glass lenses, silicone-dampened pointers, and perimeter backlighting make these instruments highly readable in all conditions.</p><p>Behind every accurate gauge reading is a properly calibrated sending circuit. Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> are a critical part of that chain, ensuring the signals from sensors and sending units are correctly interpreted by your instruments. These components are built to marine-grade standards to resist moisture, vibration, and corrosion — the realities of life on the water.</p><h3>Engine Internals Built to OEM Standards</h3><p>Sierra's history in marine power is perhaps best demonstrated by its deep catalog of engine components. The brand's <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> cover a wide range of outboard and inboard applications and are engineered to deliver reliable seals in the demanding thermal and chemical environment of a marine engine. For boaters performing seasonal overhauls, top-end rebuilds, or full engine restorations, Sierra gasket kits are a go-to resource trusted by professional marine technicians and DIY boaters alike.</p><h3>A Complete Marine Parts Partner</h3><p>Beyond instrumentation and engine internals, Sierra's catalog spans fuel systems, electrical supplies, steering components, shore power, and more — all covered by what the brand calls an industry-leading warranty. Sierra also maintains a comprehensive parts-finder tool that enables cross-referencing with OEM part numbers from major manufacturers including Mercury, Yamaha, Suzuki, Volvo Penta, and others, making it straightforward to find the right replacement part for virtually any application.</p>

Part Number

18-1827
09/11/2036 7:18 PM
Sale Price

$9.18

1 left at this price

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Product Details

The Sierra 18-1827 is a replacement water pump housing grommet designed for Johnson and Evinrude small-horsepower outboard engines. This grommet serves as a critical sealing component within the lower unit water pump assembly, helping maintain a proper seal and preventing water or air leaks that can compromise cooling system performance.

Sierra Marine replacement parts are engineered to meet or exceed OEM specifications, making the 18-1827 a reliable, direct-fit substitute for the original Johnson/Evinrude OMC part.

Key Features:

  • Direct replacement for OEM/OMC part number 321129
  • Designed for use in outboard water pump assemblies on small-horsepower engines
  • Meets or exceeds original equipment manufacturer (OEM) specifications
  • Commonly used component in water pump repair kit Sierra 18-4529 (replaces OEM 396644)
  • Sold individually

Cross-Reference Part Numbers:

  • Sierra: 18-1827
  • OEM/OMC (Johnson/Evinrude): 321129
  • GLM: 86499

This grommet is a standard service part recommended for replacement during water pump rebuilds and seasonal maintenance. Replacing worn or cracked grommets during impeller service helps ensure a proper seal and protects against cooling system failure.

Having a good cross reference to identify the proper part. Please inprove your site. Still give you a 5 star. Never stop improving. Received in a very timely manner. Thank You. Sid

Awesome

Very quick checkout!

Cheapest prices. Just waiting for the product to arrive on time. Received the other day and was pleased that the product work great. Package well and no damages. I will use your company for parts. Thank you

thx

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