Sierra Marine Water Pump Kit 18-3380 – Johnson / Evinrude 40-75HP Cooling System Rebuild
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Sierra 18-3380 Water Pump Kit is a complete cooling system rebuild kit designed for Johnson and Evinrude mid-range outboards. This kit restores proper water circulation through the engine, preventing overheating and maintaining optimal operating temperature.
This is a “without housing” kit, meaning it includes all critical internal components required to service the water pump while reusing the existing housing. Ideal for routine maintenance or resolving weak water pressure and overheating issues.
Built to meet or exceed OEM specifications, Sierra provides reliable performance and long-lasting durability for OMC outboards.
Key Features
- Complete internal water pump rebuild kit (no housing)
- Includes impeller, wear plate, cup, gaskets, seals, and hardware
- Designed for mid-horsepower OMC outboards
- Restores cooling efficiency and water pressure
- Direct OEM replacement fit and function
- Sierra lifetime warranty
Engine Compatibility
Johnson / Evinrude / OMC Outboards (1979 & Newer)
- 40 HP
- 48 HP
- 50 HP
- 55 HP
- 60 HP
- 65 HP
- 70 HP
- 75 HP
➡️ Fits 2-cylinder and 3-cylinder engines using standard (small/mid) gearcases.
These engines share similar pump designs, making this kit widely used across the mid-range OMC lineup.
Serial Number Fitment Notice
Fitment depends on gearcase type and production year.
⚠️ Always confirm:
- Engine horsepower and model year
- Gearcase type (small vs large)
- OEM part number match
Serial number verification is strongly recommended to avoid ordering the wrong kit.
When This Part Needs Replacement
Replace the water pump kit if you notice:
- Weak or intermittent telltale stream
- Engine overheating
- Reduced cooling at idle
- Impeller cracking, swelling, or hardening
- Long storage periods (dry impeller damage)
Recommended service interval: every 100 hours or annually
Installation Notes
- This kit does NOT include the housing
- Inspect housing for scoring or melting — replace if damaged
- Install impeller in correct rotation direction
- Use marine grease on impeller during install
- Ensure proper sealing of gaskets and O-rings
- Torque fasteners evenly to OEM specs
Alternate / Superseded Part Numbers
OEM Cross References
- Johnson / Evinrude / OMC:
- 0395780
- 0439071
- 0434425
- 0435147
Aftermarket Cross References
- Mallory: 9-48207
- GLM: 12090
Shipping
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
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.