Water Pump Impeller Kit – Fits Volvo Penta, Yanmar, Caterpillar, Cummins (Replaces 3841697, 877061, 21951356)

Product Details

This flexible Water Pump Impeller Kit is an essential service part for maintaining the raw water cooling system on a wide range of marine diesel engines. It is designed for direct compatibility with various Volvo Penta (30, 31, 32, 40, D4, KAD/KAMD series), Yanmar (4LH series), Caterpillar, and Cummins models, ensuring reliable performance for engine cooling.

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Volvo 3841697, 21951356, and 877061; Yanmar 127610-42200; Jabsco 920-0001; Johnson 09-1028B; and Sherwood 18200K.

• Installation Type: Direct replacement for engine raw water/seawater cooling pumps.
• Material: Engineered from high-strength neoprene rubber with a durable brass insert for longevity.
• Core Components: Each kit includes one flexible impeller and a corresponding gasket for a complete installation.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Volvo Penta engines, this impeller fits a wide range of D-series, KAD/KAMD, and TAMD/AQD models, typically in pumps with a 6-screw cover.

For Yanmar, compatibility is focused on the 4LH and 4CH series diesel engines.

For MerCruiser, this part fits several D-series diesel models, including the D4.2L variants.

Technical Specs

Product Type

Flexible Water Pump Impeller Kit

Application

Marine engine raw water/seawater cooling

Material

Neoprene rubber with brass insert

Drive Type

Spline (12 splines)

Number of Blades

8

Impeller Dimensions

65mm diameter × 50-51mm depth (2.56" × 2")

Package Dimensions

12.0" L x 10.0" W x 6.0" H

Weight

0.19 kg (0.42 lb)

Operating Temperature

-20°C to 110°C (-4°F to 230°F)

What’s in the Box

• 1 x Impeller (Replaces Volvo 3841697/21951356, Yanmar 127610-42200)
• 1 x Gasket
• 1 x Impeller Lubricant (Service kit variants only)

Note: Some kit variations may also include O-rings or a spline seal. Contents may vary slightly between manufacturers.

Installation Notes

1. Shut off the engine and close the raw water intake seacock.
2. Place a small pan under the pump to catch any drained water.
3. Remove the screws holding the water pump's cover plate.
4. Gently pry off the cover. Note the rotational direction of the existing impeller's blades.
5. Use needle-nose pliers or an impeller puller tool to grip the hub and pull the old impeller straight out.
6. Clean the inside of the pump housing and the cover plate, ensuring no old impeller pieces remain.
7. Apply a glycerin-based lubricant to the new impeller's blades and the inside of the pump housing.
8. Install the new impeller with a slight twisting motion, ensuring the blades bend in the same direction as the old one.
9. Place the new gasket on the pump body, align the cover plate, and tighten the screws in a star pattern.
10. Open the seacock, start the engine, and immediately check for proper water flow from the exhaust and for any leaks at the pump cover.

Troubleshooting & FAQ

Safety & Important Info

• Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.