Sierra International 23-3300 Replacement Impeller Kit

1. Introduction

This manual provides essential information for the proper installation, operation, and maintenance of the Sierra International 23-3300 Replacement Impeller Kit. This kit is designed as a direct replacement for Onan part number 132-0349, specifically for use in MDKAV, MDKAW (SPACESAVER), MDKAZ, MDKBD (W/ISOLATED GROUND), MDKBE (W/ISOLATED GROUND), and MDKBF (W/ISOLATED GROUND) generator models. Adhering to these instructions will help ensure the longevity and optimal performance of your marine generator's cooling system.

2. Safety Information

Always prioritize safety when working with marine engines and their components. Failure to follow safety precautions can result in injury or damage to equipment.

• Ensure the generator is completely shut down and disconnected from all power sources before beginning any work.
• Allow the engine to cool down before handling any components to prevent burns.
• Wear appropriate personal protective equipment (PPE), such as gloves and eye protection.
• Be aware of hot surfaces and rotating parts.
• Dispose of old parts and fluids responsibly according to local regulations.
• If you are unsure about any step, consult a qualified marine technician.

3. What's in the Box

The Sierra 23-3300 Replacement Impeller Kit includes the following components:

• 1 x Sierra 23-3300 Impeller
• 1 x Gasket/O-ring (for sealing the pump cover)

Image 1: The Sierra 23-3300 Impeller Kit, showing the black rubber impeller with a metal hub and a black circular O-ring.

4. Setup and Installation

This section outlines the general procedure for replacing the impeller. Specific steps may vary slightly depending on your generator model. Refer to your Onan generator's service manual for detailed instructions.

1. Preparation: Ensure the generator is turned off, cooled down, and the battery is disconnected to prevent accidental starting. Close any seacocks to prevent water ingress.
2. Access the Seawater Pump: Locate the seawater pump on your Onan generator. This may require removing covers or other components.
3. Drain Water: Place a suitable container beneath the pump to catch any draining water. Remove the pump cover bolts and carefully remove the pump cover.
4. Remove Old Impeller: Using an impeller puller tool or two screwdrivers (carefully pry on opposite sides), gently remove the old impeller from the pump housing. Note the orientation of the impeller vanes.
5. Inspect Pump Housing: Clean the pump housing thoroughly. Inspect the housing and cam for wear or damage. Replace the entire pump if significant wear is present.
6. Install New Impeller: Lubricate the new Sierra impeller with a small amount of glycerin or clean water. Align the keyway (if present) and push the impeller into the housing, twisting it clockwise to bend the vanes in the correct direction. Ensure all vanes are properly seated.
7. Install New Gasket/O-ring: Clean the gasket seating surfaces. Apply a thin layer of marine sealant (if recommended by your generator manual) to the new gasket or O-ring and place it onto the pump housing.
8. Reassemble Pump: Reinstall the pump cover, ensuring it is properly aligned. Tighten the cover bolts evenly in a crisscross pattern to the manufacturer's specified torque.
9. Reconnect and Test: Reconnect the battery, open seacocks, and start the generator. Immediately check for proper water flow from the exhaust and inspect for any leaks around the pump cover. Run the generator for a few minutes to ensure stable operation.

5. Operating Considerations

Once the new impeller is installed, proper operation of your generator's cooling system is crucial. Always monitor the generator's temperature gauge and water flow from the exhaust during operation. Any signs of overheating or reduced water discharge indicate a potential issue that requires immediate attention.

6. Maintenance

Regular inspection and timely replacement of the impeller are vital for preventing engine damage due to overheating.

• Inspection: Periodically inspect the impeller (e.g., annually or every 200 operating hours, whichever comes first) for signs of wear, cracking, or missing vanes.
• Replacement Schedule: It is generally recommended to replace impellers annually or every 200-250 operating hours, even if they appear to be in good condition. Rubber components can degrade over time due to heat, chemicals, and lack of use.
• Winterization: If operating in freezing conditions, ensure the cooling system is properly winterized according to your generator's manual to prevent damage to the pump and impeller.

7. Troubleshooting

If you experience issues with your generator's cooling system after impeller replacement, consider the following:

• No Water Flow / Overheating:
  • Check for air leaks in the suction line.
  • Verify seacock is fully open.
  • Inspect for blockages in the seawater intake or discharge lines.
  • Ensure the impeller is correctly installed and the vanes are oriented properly.
  • Confirm the pump cover gasket/O-ring is sealing correctly.
• Reduced Water Flow:
  • Partial blockage in the cooling system.
  • Impeller vanes may be partially damaged or worn.
• Leaks from Pump Cover:
  • Gasket/O-ring not seated correctly or damaged.
  • Pump cover bolts not tightened to specification or unevenly tightened.
  • Pump cover itself may be warped or damaged.

If troubleshooting steps do not resolve the issue, seek assistance from a qualified marine mechanic.

8. Specifications

9. Warranty Information

Sierra is dedicated to protecting your investment. Sierra warrants its products to be free of defects in workmanship and materials for the useful life of the product. Sierra will repair or replace the defective product free of charge, subject to conditions and limitations. All Sierra parts qualify for and are covered under Sierra's industry-leading customer satisfaction warranty.

10. Support

For additional information on the correct application of this product, technical assistance, or warranty claims, please contact Sierra International customer support through their official channels or the platform where the product was purchased (e.g., Customer Questions & Answers section).