Introduction
This manual provides essential information regarding the Sierra 18-3517 Water Pump Kit. This kit is designed for replacing the water pump components in specific marine engine applications to ensure proper cooling system function.
Compatibility
This water pump kit is compatible with the following engine models:
- Mercruiser #1 drives with flush screw in housing (Serial Numbers 2495186-2763441)
- Mercruiser #1 drives without flush screw (Serial Numbers 2763442-6854392)
- MR/Alpha 1 drives (Serial Numbers 6854393-D594568)
- Most large gearcase Mercury outboard motors (4-3/4 Gearcase)
Kit Contents
The Sierra 18-3517 Upper Housing Water Pump Kit includes the following components:
- 18-3109 Water Tube
- 18-3017 Impeller
- 18-3116 Upper Housing
- 18-2919 Water Pump Base Gasket
- 18-3110 Grommet
- 18-2945 Gear Housing to Screw Gasket
- 18-2826 Waterpump Base to Gear Housing Gasket
- 18-2914 Lower Water Pump to Wear Plate Gasket
- 18-2915 Upper Water Pump to Wear Plate Gasket
- 18-2944 Seal Ring
- 18-3117 Plate
- 18-7158 O-Ring
- 18-7162 O-Ring
- 18-7173 O-Ring
- 18-7176 O-Ring
- 18-2801 Water Pump Gasket
- 18-7196 O-Ring
- 18-7426 O-Ring
Note: This kit does not include the water pump base. If a water pump base is required, refer to SIE-18-3320 for Mercruiser Sterndrives or consult the Mercury Water Pump Application Chart for Mercury Outboard applications.
An image displaying all components included in the Sierra 18-3517 Water Pump Kit. These include various gaskets, O-rings, an impeller, a water tube, an upper housing, a seal ring, and a plate, laid out on a white background.
Installation Guidelines
Proper installation of the water pump kit is crucial for optimal engine performance and longevity. Due to the complexity of marine engine systems, it is highly recommended that installation be performed by a qualified marine technician.
Refer to your specific engine's service manual for detailed, step-by-step instructions, torque specifications, and any special tools required for the water pump replacement procedure.
General Steps (Consult Service Manual for Details):
- Disconnect battery and ensure engine is cool.
- Drain gearcase lubricant if necessary.
- Remove the lower unit or gearcase from the engine.
- Disassemble the existing water pump housing and components.
- Clean all mating surfaces thoroughly, removing old gasket material.
- Install new components from the Sierra 18-3517 kit, ensuring correct orientation of the impeller and proper seating of all gaskets and O-rings.
- Lubricate O-rings and seals as specified by the service manual.
- Reassemble the water pump housing and lower unit/gearcase, adhering to all torque specifications.
- Refill gearcase lubricant and reconnect battery.
- Perform a functional test in a controlled environment (e.g., with muffs or in water) to check for proper cooling water flow and leaks.
Operation Considerations
After installation, ensure the engine's cooling system operates correctly. Monitor engine temperature during initial operation. A properly functioning water pump is essential for preventing engine overheating.
Always ensure adequate water supply to the engine's cooling system when operating, especially during flushing or testing on land.
Maintenance
Regular inspection and maintenance of your marine engine's cooling system are vital. The water pump impeller is a wear item and should be inspected or replaced periodically, typically every 100 hours of operation or annually, whichever comes first.
Signs of a failing water pump or impeller include:
- Reduced water discharge from the tell-tale (pee hole).
- Engine overheating.
- Unusual noises from the water pump area.
Always use genuine or equivalent quality replacement parts for maintenance.
Troubleshooting Common Issues
If you experience issues related to the cooling system after installing the water pump kit, consider the following:
- No or Low Water Flow: Check for obstructions in the water intake, ensure the impeller is correctly installed and not damaged, and verify all gaskets and seals are properly seated to prevent air leaks.
- Engine Overheating: This can indicate insufficient water flow. Re-check impeller installation, thermostat function (if applicable), and ensure no blockages in the cooling passages.
- Leaks: Inspect all gasket and O-ring locations for proper seating and damage. Ensure all fasteners are torqued to specification.
For persistent issues, consult a qualified marine technician.
Specifications
- Part Number: AMRS-18-3517
- Replaces Mercury Part Numbers: 46-60367A1, 46-96148A5, 46-96148A8
- Replaces Mallory Part Number: 9-48311
- Replaces Redline Part Number: 3517
- Kit Type: Upper Housing Water Pump Kit
- Application: Mercruiser Alpha One Drives & Mercury 4-3/4 Gearcase Outboards
