Engine impeller replacement

[kwbybee]

I have a 2003 300 Sundancer with 350 MAGS and need to replace the raw water impellers. Any quick advice on how to do that. I mechanically able to do it, just need some pointers.

 

[NautyDog]

What type of drives do you have? This makes a difference in where the impellers are and how they are changed.

 

[dsteele1]

Here's a couple of prevoius links. I still haven't tried doing this myself in the water...

http://www.sterndrives.com/rebuild_bravo_raw_waterpump.html

http://www.clubsearay.com/forum/showthread.php?t=414&page=7

http://clubsearay.com/forum/showthread.php?t=4878&highlight=impeller+replacement

Hope this helps! :grin:

 

[KayKook]

From one of the articles. "The Raw Water pump should be rebuilt every season."

You gotta be kidding me, maybe every 3 or 4 seasons.

 

[wish2fish]

if mine was more easily reached I would replace every season!

 

[RUMNCOKE]

The impeller replacement is not a bad job. Start by removing the alternator then the pulley bracket. Then remove the 3 way hoses. Remove the fuel transmitter assembly by removing the 4 10mm bolts and set it to the side. Do not remove the fuel lines. This would be a good time to also replace the fuel filter if you have enough hrs. You can now get to the raw water pump. Pull it forward and remove the water hose clamps and slide the hoses off of the pump. When you open the pump be sure to note the direction of the impeller rotation. The new impeller will come with a new seal. A nice trick to replace the seal is to remove the old seal from the housing and fill that area with petrolum jelly and press the seal into the jelly. The seal will conform to the housing and not pop out during assembly. Just reverse the dissassembly process and you will be up an running in about 3-4 hours with basic hand tools.

 

[NautyDog]

A nice trick to replace the seal is to remove the old seal from the housing and fill that area with petrolum jelly and press the seal into the jelly. The seal will conform to the housing and not pop out during assembly.

Petroleum Jelly (i.e. Vaseline) is actually corrosive to O-Rings in general. I use Silicone Grease which is what service manuals state (when the recommend this trick). It's hard to find Silicone Grease, but Dive Shops sell it (for this exact reason - to coat O-Rings). Also, you can find various brands on the internet (i.e. Sea & Sea).

Finally, make sure you coat the impeller in soapy water. This is supposed to help lubricate the impeller upon the initial dry start up, while then washing away quickly.