Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP (Replaces 46-99157T2, 46-85098A2)
Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP (Replaces 46-99157T2, 46-85098A2) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
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Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP (Replaces 46...
Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP (Replaces 46-99157T2, 46-85098A2) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP is engineered to service the upper water pump assembly on a range of Mercury and Mariner outboard engines. It provides a reliable solution for 2-Stroke models from 15–25 HP (1980–1998) and 4-Stroke models from 9.9–15 HP (1995–2006).
This kit serves as a direct replacement for Mercury OEM part numbers 46-99157T2, 46-99157A2, 46-85098A2, 85098A2, 99157A2, and 99157T2.
- Compatible with upper water pump installations.
- Features a durable SS316 stainless steel housing for corrosion resistance.
- Includes a high-performance neoprene marine rubber impeller.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket parts.
| Brand | Part Number |
|---|---|
| Mercury | 46-99157T2 |
| Mercury | 46-99157A2 |
| Mercury | 46-85098A2 |
| Mercury | 85098A2 |
| Mercury | 99157A2 |
| Mercury | 99157T2 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury/Mariner owners, please verify your engine's serial number against the notes provided to ensure an exact match.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury/Mariner | 15 XD Bigfoot | 15 | 2-Stroke | 1997–1998 | 46-99157T2 | Serial #9927000 & Up |
| Mercury/Mariner | 18, 18XD | 18 | 2-Stroke | 1980–1985 | 46-99157T2 | USA Serial #5837437 & Up, AUS Serial #8071973 & Up, BEL Serial #9308306 & Up, CAN Serial #7209608 & Up |
| Mercury/Mariner | 20, 20XD | 20 | 2-Stroke | 1986–1987 | 46-99157T2 | USA Serial #6443973-0T800749, BEL Serial #9415101 & Up, CAN Serial #7209533 & Up |
| Mercury/Mariner | 25, 25XD | 25 | 2-Stroke | 1980–1987 | 46-99157T2 | USA Serial #5705532 & Up, AUS Serial #8073158 & Up |
| Mercury/Mariner | 25 (3-Cylinder) | 25 | 2-Stroke | 1997 & Up | 46-99157T2 | Serial #0E268781 & Up |
| Mercury/Mariner | 25 Sea Pro/Marathon/Super 15 | 25 | 2-Stroke | 1988–1994 | 46-99157T2 | BEL Serial #9507381 & Up, CAN Serial #0A730007 & Up |
| Mercury/Mariner | 25 Sea Pro/Marathon/Super 15 | 25 | 2-Stroke | 1988–1998 | 46-99157T2 | USA Serial #0B238464 & Up |
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury/Mariner | 9.9 Bigfoot | 9.9 | 4-Stroke | 1995–1998 | 46-99157T2 | USA Serial #0G760300-0T979999, BEL Serial #0P075166-0P325499 |
| Mercury/Mariner | 15 Bigfoot | 15 | 4-Stroke | 1998 | 46-99157T2 | USA Serial #0G590000 & Up, BEL Serial #9973100 & Up |
Technical Specs
- Product Type
- Water Pump Repair Kit
- Installation
- Upper Water Pump
- Housing Material
- Stainless Steel (SS316)
- Impeller Material
- Neoprene Marine Rubber
- Gasket Material
- Non-asbestos
What’s in the Box
- 1 x Pump Housing Assembly (Replaces 99157A02, 99157A1)
- 1 x Impeller (Replaces 8508910, 47-85089-3, 47-85089-10)
- 1 x Face Plate (Replaces 85083)
- 1 x Gasket (Replaces 993261)
- 1 x Key (Replaces 8M0032838)
- 1 x Seal (Replaces 85090001, 85090)
- 2 x Washer (transparent) (Replaces 12-86645-1)
- 4 x Insulator (Replaces 23-85095)
- 3 x O-ring
- 1 x Water Tube Guide Sleeve
Installation Notes
- Disconnect the battery and remove the engine cover.
- Drain the gearcase oil from the lower unit.
- Remove the bolts securing the lower unit (gearcase) to the engine's midsection and carefully lower it.
- Locate the water pump housing on top of the gearcase. Remove its mounting bolts to expose the impeller and internal components.
- Remove the old impeller, face plate, gaskets, and seals. Clean all surfaces thoroughly.
- Install the new gasket, face plate, and impeller from the kit. Ensure the impeller key is correctly seated on the driveshaft.
- Lubricate the inside of the housing and the new impeller with a marine-safe lubricant.
- Re-install the water pump housing and tighten the bolts to the manufacturer's specified torque.
- Re-attach the lower unit to the engine, ensuring the driveshaft and water tube are properly aligned.
- Refill the gearcase with fresh oil, reconnect the battery, and test the engine in water to verify proper cooling.
Troubleshooting & FAQ
How do I confirm this kit fits my specific engine?
Check the compatibility tables and verify your engine's model, horsepower, and year range. Most importantly, match your engine's serial number with the ranges listed in the 'Notes' column for a precise fit.
What are common signs of a failing water pump?
The most common sign is engine overheating at idle or low speeds. You may also notice a weak or inconsistent stream of water from the tell-tale outlet. Reduced engine performance can also indicate a cooling problem.
How often should the water pump impeller be replaced?
As a preventative maintenance measure, it's recommended to inspect the impeller annually and replace it every 1-2 years (or every 100-200 hours of use), depending on operating conditions. More frequent replacement may be needed in sandy or saltwater environments.
Can I install this repair kit myself?
While DIY installation is possible for those with mechanical experience, professional installation is recommended to ensure safety and correct function. The process involves handling the lower unit, which can be heavy and requires careful alignment during reassembly.
My engine still overheats after replacing the kit. What could be the issue?
If overheating persists, check for other blockages in the cooling system, such as clogged intake screens, a faulty thermostat, or debris in the engine's internal water passages. Also, ensure the water tube was correctly aligned during installation.
Is this an OEM part or an aftermarket one?
This listing is for an aftermarket replacement, not an OEM component. It is built to meet or exceed OEM-level specifications using comparable high-quality materials and is manufactured in an ISO 9002 certified facility with batch inspections for quality assurance.
How fast is shipping and what are the costs?
We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free. If available for your location, expedited shipping options and their costs will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. Should an issue arise, contact our support team with your order details. Returns of unused items in their original condition are accepted within our standard return window. Please see our full policy page or contact us for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component.
- Professional installation is strongly recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical arrival in 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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