Sierra 18-3600

SKU: 4003654 - UPC: 808282286507 - MPN: 18-3600
$598.99 $704.69 ( / )

Available Stock : 6

Upgrade Your Mercury V8 Engine Cooling System with Confidence Keeping your boat's engine running cool under demanding conditions starts with a robust water pump base. The Sierra 18-3600 delivers OEM-level performance, engineered to handle the rigors of marine environments. Crafted from corrosion-resistant materials, it ensures reliable water flow to prevent...
Sierra Engine Parts
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Sierra 18-3600 Product Description

Upgrade Your Mercury V8 Engine Cooling System with Confidence

Keeping your boat's engine running cool under demanding conditions starts with a robust water pump base. The Sierra 18-3600 delivers OEM-level performance, engineered to handle the rigors of marine environments. Crafted from corrosion-resistant materials, it ensures reliable water flow to prevent overheating during long hauls or high-speed runs.

Unlike stock components that wear down from constant exposure to saltwater and debris, this precision-machined replacement stands up to the elements. Boaters trust it for seamless integration, restoring factory cooling efficiency without the premium price tag.

Perfect Fit for V8 Engines with V-Belt Drive and 2-Piece Pumps

Designed specifically for Mercury V8 outboards featuring V-belt drives and two-piece pump setups, the Sierra 18-3600 slots in effortlessly. It replaces the original Mercury 46-72774A32, matching exact specifications for bolt patterns, gasket surfaces, and mounting points.

  • Ideal for high-performance V8 models where cooling reliability is non-negotiable
  • Compatible with a range of horsepower ratings common in recreational and commercial boating
  • Pair it with Sierra repair kit 18-3155 for complete pump rebuilds and optimal impeller seating

Before installing, double-check your engine's pump configuration—V-belt drive and two-piece design are key indicators for a hassle-free swap.

Step-by-Step Installation for DIY Boaters

Swapping out your water pump base doesn't require a marine mechanic. With basic tools and a dry workspace, most installs take under an hour. Here's a proven approach:

  1. Drain the cooling system and remove the lower unit or pump assembly per your engine manual.
  2. Inspect and clean mating surfaces; replace gaskets if worn.
  3. Secure the new base with factory torque specs (typically 10-15 ft-lbs—consult service guide).
  4. Reassemble the two-piece pump, insert the impeller from kit 18-3155, and test for leaks.
  5. Prime the system and run at idle to verify flow.

Pro tip: Apply marine-grade anti-seize to bolts for future ease, and always flush with fresh water after saltwater use to extend component life.

Maximize Longevity: Essential Maintenance Practices

A well-maintained water pump base like the Sierra 18-3600 can last seasons without issues. Watch for these early warning signs of trouble:

  • Steam from the powerhead or rising temps on gauges
  • Reduced pee stream from the tell-tale outlet
  • Galvanic corrosion around mounting holes

Annual inspections during off-season storage catch problems early. Rebuild the full pump every 2-3 years or 300 hours, using genuine Sierra kits for impeller, housing, and wear plate refresh. This simple routine safeguards your V8 investment against catastrophic failures.

Why This Part Delivers Superior On-Water Results

Boaters rave about the Sierra 18-3600's durability in real-world scenarios—from choppy bays to tournament fishing. It promotes consistent coolant circulation, reducing hot spots that lead to warped heads or seized pistons. Lightweight yet sturdy, it won't add unnecessary drag to your propulsion system.

Investing here means fewer breakdowns, more time on the water, and peace of mind knowing your cooling system matches the power of your V8.

Frequently Asked Questions

What engines does the Sierra 18-3600 fit?

It fits Mercury V8 outboard engines equipped with V-belt drives and 2-piece water pumps, directly replacing part 46-72774A32.

Do I need the 18-3155 repair kit with this part?

Yes, for a full service, pair it with the 18-3155 kit to replace the impeller, wear plate, and key—ensuring peak cooling performance.

How do I know if my pump is a 2-piece design?

Look for a separable housing with an impeller cartridge inside the main base; V-belt driven pumps on V8s typically match this setup.

Can I install this without pulling the lower unit?

Usually yes, but access varies by model—remove the pump assembly first for best results and to inspect gears.

What materials make this part corrosion-resistant?

High-grade aluminum alloy with protective coatings combats saltwater pitting and galvanic action effectively.

How often should I replace the water pump base?

Inspect yearly; replace if corrosion or wear appears, or during impeller rebuilds every 2-3 years.

Will this restore full cooling capacity?

Absolutely—precise tolerances match OEM specs, delivering unrestricted water flow to critical engine areas.

  • Replaces: Mercury #46-72774A32

  • Fits: V8 Engines w/ith V-Belt and 2 piece pump

  • Use repair kit 18-3155




Save $105 when you buy the Sierra 18-3600 for only $598 from NVN Marine! Same day shipping before 3pm.

Sierra 18-3600 Technical Specifications

Type: 

Engine | Parts / Drive

Vendor: 

Sierra Engine Parts

Weight: 

7.08 lb

Sierra 18-3600 User Reviews

Sierra 18-3600 Shipping & Return

Shipping Weight: 

7.08 lb

Box Sizes: 

4.00 (h) x 5.00 (w) x 11.00 (l)

Cubic Feet: 

220.0

Returnable: 

Yes

For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.

Sierra 18-3600

$598.99 $704.69 ( / )