PDA

View Full Version : when to change impeller



lovemyultra
04-05-2003, 01:30 PM
How many seasons does everybody put on a Bravo 1 impeller and housing ? I have been doing mine every other season and had no problems .Just seeing how everyone else does it

77charger
04-05-2003, 04:44 PM
i need to know that one also i have an alpha drive also have a spare impeller too.Boat has 225 hrs

rrrr
04-05-2003, 05:59 PM
Every other year for my B1 impeller, the housing lasted for four seasons before I changed it.
Every time I have changed the impeller it has had cracks on the vanes.
Don't forget to grease the coupling on the flywheel too. It's a $1,500 repair job if you neglect it.

Trash
04-05-2003, 10:38 PM
Okay, I must be the luckiest guy out there, but my pumps are all original and going on 8 years. Just shy of 500 hours. Not recommending going that long for anyone out there. I also guess I'm due to get a tow to the docks sometime for this.

mtndewdrops
04-11-2003, 08:02 PM
I owned a 96 Maxum with a 5.7L Alpha I and put 4 seasons on it without changing the impeller. eek! It was mostly used on Parker Strip and Lake Havasu.
Now that I stepped up to a 99 Essex Sterling with a 350 Mag Bravo III :cool: I am going to replace it every other year as well.
Luckily the guy I bought the boat from had just replaced it. wink

wakemaker
04-14-2003, 09:07 PM
last one i did it had 5 seasons and about 130 hours on it, it still looked new, i was told if you run them dry they will last a long time but some shops i talked to said every other year. im on the 5th season since the last one.

wakemaker
04-14-2003, 09:11 PM
oops make that dont run them dry ie with out water at the out drive, sorry first post.
i need to go to the river bad!!!

Trash
04-14-2003, 10:31 PM
I never run the thing dry, even for a second. Maybe that's why I'm so lucky. I know the Merc manual says it only takes 10 seconds to destroy the pump without water in it.

Fat Chance
04-22-2003, 04:18 PM
So I'm on the same page...We are talking about the impellae in the water pump on the front of the motor, correct? I've heard conflicting info that there is also a impeller in the outdrive...is that true for a B1? As far as the water pump, I too change the impeller and case every other year, better safe then sorry!

boaterh
04-22-2003, 04:35 PM
My Alpha 1 drive went 15 years and around 200hours on the original pump. When it was removed, it looked like new and was still flexible.I'm hearing the engine mounted water pumps for the heat exchanger on the 496 closed cooling system last around 2 years.

Zuumer
04-22-2003, 04:57 PM
There are two different types of impellers. The one for the Alpha drive is in the lower unit and is identical to the outboards. This should be changed at least every two years with moderate use or once a year for heavy use. Make sure you install the whole kit rather than just the impeller. The kit has a metal rub plate that replaces the installed one which will more than likely have a groove worn in it resulting in a loss of water pressure. It's kinda like changing a clutch...while it's apart change the throw-out bearing.
The Bravo drive has no internal impeller but rather a belt driven pump on the front of the engine on the lower starboard side. This impeller should be changed when "a decrease in water pressure is noted" according to Mercury. If you're pumping good water and the engine temp is within normal limits...you should be good to go. However, if the boat sits for long periods of time, the impeller on either the Alpha or the Bravo pumps will "take a set" and not push as much water as with a new one.
As with all of our boating stuff...if you have a doubt..change it. It's cheap insurance. :) :)

lovemyultra
04-22-2003, 06:42 PM
Thanks for the help it was no big deal to change and only around 65 bucks THANKS AGAIN

Fat Chance
04-22-2003, 09:11 PM
Thanks for clear'n that up Zuumer.
[ April 22, 2003, 10:11 PM: Message edited by: Fat Chance ]

Zuumer
04-23-2003, 06:08 AM
Fat Chance:
Thanks for clear'n that up Zuumer. Glad to help :) :)