How to Replace a Volvo Penta Inboard Outboard Impeller

Written by chris stevenson
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Replace a Volvo Penta Inboard Outboard Impeller
(Jupiterimages/ Images)

Boats rely on external inlets to suck water into the engine to cool down the working parts. The water pump has the important job of circulating water through the engine passages by using a neoprene impeller that rotates within a pump housing. The blades on the impeller act like a vane, drawing water through an inlet side and discharging it out another side. The very nature of rubber impellers makes them susceptible to splitting, breaking or wearing out over a length of time.

Skill level:

Things you need

  • Boat owner's manual
  • Socket set
  • Ratchet wrench
  • Screwdrivers
  • Drain pan
  • Emery cloth
  • Gasket scraper
  • Carburettor cleaner
  • Rags
  • Glycerine lubricant
  • Water pump impeller kit

Show MoreHide


  1. 1

    Trailer the boat and transport it to a convenient maintenance location. Activate the main ignition cut-off switch at the control panel. Open up the battery box and disconnect the negative battery cable with a socket. Unclasp the engine case cowl snaps and stow the case aside. Refer to your owner's manual for the location of the water pump case housing. It will be fitted to the harmonic balancer on the low, front part of the engine.

  2. 2

    Place a drain pan under the two large hoses that connect to the pump housing -- the intake and discharge hoses. Depending upon the fastener device, use a screwdriver or small socket to loosen the hose clamps. Twist the hoses back and forth and pull them off pump housing necks. Place a socket on the outside mounting bolts to the water pump case housing. Unscrew them counterclockwise.

  3. 3

    Use a flat blade screwdriver to wedge the outer pump casing off the harmonic balancer. Pull the small seal ring out of its depression on the shaft. Flip the pump housing upside down. Note the impeller blade orientation, and remember it.

  4. 4

    Pull off the old O-ring rubber gasket from the harmonic balancer shaft lip and discard it. Pull the old impeller out and discard it. Use some carburettor cleaner and a gasket scraper to clean the mating surfaces of the pump housing and harmonic balancer. Wipe both surfaces with a rag.

  5. 5

    Use emery cloth to lightly sand the inside of the impeller housing. Wipe it clean with carburettor cleaner and a rag. Place the new (kit) seal ring in its depression over the shaft. Apply some glycerine lubricant to the new (kit) O-ring seal and place it on the harmonic balancer shaft lip.

  6. 6

    Place the new impeller inside the pump housing, aligning the blades in the orientation you removed them. Set the pump housing back on the harmonic balancer and insert the four mounting bolts in the thread holes by hand.

  7. 7

    Tighten the pump housing bolts with a socket and wrench in a crisscross pattern. Attach the discharge and intake hoses back onto the water pump housing necks. Tighten the clamps with a screwdriver or socket. Remove the drain pan. Reinstall the engine cowl case, clasping the hold-down snaps.

  8. 8

    Reconnect the negative battery cable to its post and tighten the battery clamp with a socket. Reactivate the main ignition cut-off switch if you wish to test the engine, but only test the engine by submerging the hull in water.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.