Sierra Impeller 18-3068 (AP-2009) – Mercury / Mariner Outboard Water Pump Replacement
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Sierra 18-3068 Impeller (AP-2009) is a direct replacement raw water pump impeller designed for Mercury and Mariner outboards. This impeller plays a critical role in circulating cooling water through the engine, helping maintain proper operating temperature and preventing overheating.
Constructed from high-quality flexible rubber and engineered to meet or exceed OEM specifications, this impeller ensures dependable performance and long service life in both freshwater and saltwater environments.
Ideal for routine maintenance, replacing your impeller helps restore full cooling system efficiency and protects your engine from heat-related damage.
Key Features
- Direct replacement raw water pump impeller
- Flexible rubber vanes for efficient water flow
- Precision-fit hub for secure installation
- Maintains proper engine cooling performance
- Durable marine-grade construction
- Sierra limited lifetime warranty
Engine Compatibility
Mercury / Mariner Outboards
Commonly used on:
- 8 HP
- 9.9 HP
- 15 HP
➡️ Fits select small horsepower Mercury/Mariner outboards (2-stroke and early 4-stroke models).
Serial Number Fitment Notice
Fitment depends on:
- Engine model and year
- Water pump housing type
- Shaft spline configuration
⚠️ Always confirm using:
- Engine serial number
- OEM part number match (18-3068 / AP-2009)
When This Part Needs Replacement
Replace the impeller if you notice:
- Weak or no telltale stream
- Engine overheating
- Reduced cooling performance
- Cracked, hardened, or missing vanes
- After seasonal storage
Recommended service interval: every 100 hours or annually
Installation Notes
- Lubricate impeller before installation
- Install with correct vane rotation
- Inspect housing and wear plate
- Ensure proper key alignment
- Replace seals/gaskets if worn
Alternate / Superseded Part Numbers
OEM Cross References
- Mercury: 47-89980, 89980T, 89980T1
Aftermarket Cross References
- Sierra: 18-3068
- Mallory: 9-45600
- GLM: 12017
Shipping
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
💡 Parts Desk Insight
On smaller outboards, cooling issues often show up slowly—like a weaker telltale stream. That’s usually your first sign the impeller is wearing out.
Swapping it regularly is quick, inexpensive, and one of the best ways to keep your motor reliable 👍
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.