Jabsco Impeller Guide
The Ultimate Jabsco Impeller Guide | Maintaining Your Cooling System
The Ultimate Jabsco Impeller Guide | Maintaining Your Cooling System
If you own a boat, you know that the hum of your engine is only as reliable as the water flowing through it. The impeller is the heart of your engine's cooling system, pumping raw water to keep temperatures stable. But because these flexible rubber fins are constantly working, they eventually wear out, stiffen, or tear.
Ignoring a worn impeller is a recipe for an overheated engine and a very expensive tow. Here is everything you need to know to swap yours out like a seasoned marine mechanic.
Phase 1: Preparation & Parts
Before you crack open the pump, make sure you have the right gear. Jabsco pumps vary by model, so check your engine manual or the pump faceplate for the part number.
What You’ll Need:
* A New Jabsco Impeller Kit: (Includes the impeller, O-ring/gasket, and lubricant).
* Screwdriver or Socket Wrench: For the pump cover screws.
* Needle-nose Pliers or an Impeller Puller Tool.
* Gasket Scraper: To clean the mating surface.
* Marine Grease or Glycerin: (Usually included in the kit).
> Pro Tip: Don’t play "guess the part number" at the local hardware store. For guaranteed fitment and OEM quality, head over to MacombMarineParts.com. They carry a massive inventory of Jabsco components to ensure you’re getting the exact specs for your specific engine model.
Phase 2: Step-by-Step Replacement
1. Close the Seacock
Safety first! Locate the intake valve (seacock) and turn it to the OFF position. If you skip this, you’ll have a mini-geyser in your bilge the moment you pull the cover off.
2. Remove the Pump Cover
Use your wrench or screwdriver to remove the screws on the circular brass faceplate of the Jabsco pump.
* Pro Tip: These screws are small and love to jump into the bilge. Keep a magnetic tray or a small cup nearby to catch them.
3. Inspect the Gasket
Once the cover is off, remove the old O-ring or paper gasket. If it’s stuck, use a scraper gently—you don’t want to gouge the brass surface, as this will cause leaks later.
4. Extract the Old Impeller
This can be the toughest part. If the impeller is stuck:
* Use an impeller puller tool for a straight, even tug.
* If using pliers, be careful not to mar the pump housing.
* Check for missing fins: If the old impeller is missing "teeth," you must find them. They often migrate into the heat exchanger or oil cooler, causing clovers that lead to overheating even with a new part.
5. Lubricate and Install
Apply the provided glycerin or a water-soluble lubricant to the inside of the pump housing and the fins of the new impeller. Never use petroleum-based grease, as it can degrade the rubber.
* The "Twist and Push": Insert the impeller with a clockwise twisting motion. This pre-bends the fins in the correct direction. Don't worry if you twist it the "wrong" way; the engine's first revolution will usually flip them, but starting them correctly reduces initial stress.
6. Seal and Secure
Place the new gasket or O-ring on the housing. Replace the cover and tighten the screws in a star pattern to ensure even pressure.
Phase 3: The Test Run
Open the seacock (don't forget this!) and start the engine. Head to the stern and check the exhaust. You should see a steady stream of water within 30 seconds. If not, shut it down immediately and check for air leaks at the pump cover.
Pro Tips for Longevity
* The Annual Swap: Even if your boat sits, the impeller fins take a "set" (curving permanently), which reduces efficiency. Replace it every season or every 200 hours.
* The Spare Rule: Always keep a spare kit from MacombMarineParts.com on board. An impeller failure in the middle of a lake or ocean is a 15-minute fix if you have the part, but a ruined weekend if you don't.
* Winterization: If storing for the winter, some captains remove the impeller entirely to prevent the rubber from cracking under tension.
Ready to get your cooling system back in peak shape? Visit MacombMarineParts.com today to find your specific Jabsco impeller kit and any specialized tools you need to get the job done right the first time.
See our collection of impellers here!
Jabsco Impeller Guide