Volvo Penta Impeller Kit 21700445 – OEM Raw Water Pump Service Kit
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Volvo Penta OEM Raw Water Pump Impeller Service Kit – Part No. 21700445
Part Number: 21700445
Brand: Volvo Penta
Product Type: OEM Raw Water Pump Impeller Service Kit
System: Raw Water (Sea Water) Cooling System
Drive Type: 5/8" Spline
Blade Count: 12-blade flexible rubber impeller
Approximate Impeller Dimensions: 2-1/4" diameter × 1-7/8" width
The genuine Volvo Penta OEM raw water pump impeller service kit for modern V8 gasoline marine engines. This complete kit includes the impeller plus all sealing components and hardware required for a full raw water pump service — restoring reliable coolant flow and protecting your engine from overheating.
Kit Contents
- 12-blade flexible rubber impeller (approx. 2-1/4" dia. × 1-7/8" width)
- 5/8" spline drive hub
- Pump cover O-ring
- Additional O-rings
- Cover bolts
- Lock washers
Compatible Applications
- Volvo Penta V8-350-C-D
- Volvo Penta V8-350-CE-D
- Volvo Penta V8-380-C-A / C-B / C-D
- Volvo Penta V8-380-CE-A / CE-D
- Volvo Penta V8-430-CE-D
- Additional Volvo Penta gasoline engines fitted with a compatible raw water pump — verify by engine serial number and parts diagram
Always confirm fitment using your engine serial number and the correct parts diagram before ordering. Pump mounting style and serial number range affect compatibility.
Service Interval
Replace every 100 operating hours or annually — whichever comes first. Impeller vanes harden and crack over time, particularly after dry running or extended storage. Scheduled replacement is the most effective way to prevent raw water pump failure and engine overheating.
Installation Notes
- Lubricate the impeller with clean water or a compatible lubricant before installation
- Install with the correct vane rotation direction — refer to your engine service manual
- Replace all O-rings and seals included in the kit — do not reuse old seals
- Inspect the pump housing and wear plate for scoring before installing the new impeller
- Use a dedicated impeller puller tool for removal to avoid damaging the pump housing — see Volvo Penta Impeller Puller Screw 3843949
Technical FAQ
Q: How do I know if my impeller needs replacing?
A: Common signs include reduced cooling water flow from the exhaust, engine overheating under load, or visible cracking and stiffness in the impeller vanes. Even if vanes look intact, annual replacement is recommended — rubber degrades from heat and age regardless of visible wear.
Q: What happens if impeller vanes break off?
A: Broken vane fragments can travel through the cooling circuit and block the heat exchanger or thermostat housing. If you find a damaged impeller, inspect the entire cooling system for debris before running the engine.
Q: Do I need a special tool to remove the impeller?
A: A dedicated impeller puller is strongly recommended. Prying the impeller out risks damaging the pump housing. See the Volvo Penta Impeller Puller Screw 3843949.
Q: Can I reuse the old O-rings?
A: No — always replace all O-rings and seals included in the kit. Reusing compressed or aged O-rings is a leading cause of post-service cooling leaks.
Q: Do I need the full kit or just the impeller?
A: We recommend the full kit. The cost difference is minimal, and replacing all seals and hardware at the same time eliminates the most common cause of post-service leaks.
Parts Desk Insights
Best Use Case: This is the go-to annual maintenance item for Volvo Penta V8 sterndrive owners. The higher blade count and splined hub on these newer V8 pumps move more water at higher RPM than older designs — which means a worn or cracked impeller has a greater impact on cooling performance. If you're seeing cooling drop-off under load or at higher speeds, the impeller is the first place to look.
Common Issue: Post-service cooling leaks caused by reusing old O-rings. Replace everything in the kit — it's included for a reason. Using a proper impeller puller also prevents pump housing damage during removal, which is a frequent avoidable repair cost.
Related Parts
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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