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Sierra 18-70925 Molded Cooling System Hose for MerCruiser Stern Drives

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-70925
07/13/2036 2:53 PM
Sale Price

$30.08

4 left at this price

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-70925 is a replacement molded cooling system hose designed specifically for MerCruiser stern drive engines. This hose connects the thermostat cover to the port manifold, providing a critical pathway for coolant circulation in your marine engine's cooling system.

Key Features:

  • Precision-molded design ensures proper fit and routing
  • Compatible with MCM/MIE V-6 and V-8 engines (305 and 350 cubic inch displacement)
  • Fits 4.3L, 5.0L, and 5.7L MerCruiser engines
  • Manufactured to meet OEM specifications for reliable performance
  • Durable construction designed to withstand marine environment conditions

This hose replaces Mercury/MerCruiser OEM part numbers 32-160211, 32-87116, and 32-16021, as well as Mallory 9-44056. Sierra marine engine parts are engineered to meet or exceed original equipment specifications, ensuring proper fit and long-lasting performance in your cooling system.

Good

Parts in stock. Competitive prices. Fast standard shipping. Thank you.

Returning customer after finding great rates and having a quick easy experience.

Web site has a lot of items without much description.

Picture was different then real product had to call to confirm fitment and was giving good answers.

very good price fast shipping

they were able to answer any questions i had and shipped the item out the next day. great to do business with. i will be ordering from them again.

Great experience. I would definitely recommend.

These guys are awesome. I placed my order and shipped out asap. Live inventory is amazing. All the parts I needed were in stock and shipped to me.

great and easy...

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