Can you replace a bravo 3 impeller while the boat is in the water

tony1b2000

tony1b2000

Active Member
Oct 10, 2007
243
Salem MA
Boat Info
Carver C37
Engines
Mercury Diesel 4.2 TDI, inboards
Hi Folks,

I have 496 mags with the pump on the engine. Unfortunately, there are no seacocks to shut the water coming in from the drives.
I was able to get the pump unbolted from the engine and ready to pull. But I am hesitant as to how to slow the water down when I disconnect the pump from the intake hose.

Suggestions? Or should I have the boat hauled out of the water?

Thanks !
 
It can be done. Once you pull the "hard" suction hose off pick it up higher than the water level on the outside of the boat and it will not flow. To take it one step further you can plug the hose with a large bolt or something similar and tighten the clamp.
 
And I suggest that you don't leave the boat unattended while the hose is off.
 
The safest way is to haul the boat. That said, you can remove the inlet hose and install some kind of plug while you remove the pump to replace the impeller. The challenge will be removing the plug and re installing the hose while water is pouring in.
You are probably limited on room where the pumps are located already. Is it possible, yes. In an emergency sure. If I had the option I would haul the boat and take my time. I just did mine and I pulled the pump while in the water, but had boat hauled afterwards while I rebuilt the pump. (I dry stack). You really want to be able to make sure the inlet hose is installed all the way on the pump and that the clamp is located properly and tightened securely. Use new clamps.
 
My mechanic did my last boat twice while in the water. As mentioned, lift hose above waterline and plug it for safe measure. If not mistaken, I think a C or D battery was the right sized plug....can't recall which.
 
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When I did the water pump on my 260DA with a Bravo3 in the water I just plugged the inlet with the handle of a large screw driver. Keeps the water flow to just a few drops. As mentioned previously I would not leave the boat unattended but I also would not worry about letting in a very little bit of water.

-Kevin
 
Thanks for the advice! I called around to get a price on a haul out. Price was between $450 and $600. So that's out of the question.
I did pick up some wood tapered dowels at West just to try out to plug the hose. It's just a scary though seeing the ocean poring into the boat!
 
I haven't done this, but a fellow boater did his in the water one year and it worked out ok. So the next time he had the boat pulled, closest marina is 90 minutes away, he put in line brass gates in the line. Now he does it in the water without a hitch. Just turns the valve off, does the change over and turns the valve on. Works great.
 
You could plug the hose fitting on a muff and slip that over the drive inlet - it will help to slow down the incoming water. I've never tried it, personally, but it seems like a good/easy thing to do.
 
I changed mine several times in the water - I took a cutoff broomstick, wrapped a rag around it and stuffed it into the hose and put a clamp on it. Barely leaked a drop - putting it back on is a little spirited, trying to get it back on the pump with water rushing in, but it's doable.
 
Yes and keep it simple. Get a set of long nose flat vice-grips and thick rag. Clamp the raw water hose coming into the pump. Don't smash it just clamp it firmly. It doesn' take much but you'll have a dry boat while working on the pump. Use the rag to protect the hose.

If there is a wire in the hose then yes plug it. They sell wood plugs for all size hoses. In this process don' t leave the boat...
 
Locks automatically. read the reviews too. Good tool to have on a boat. I wish it were stainless steel.
 
Be careful pinching that hose. Most inlet hoses have a wire so they don't collapse from the pump "sucking" water in from the drive.
I have changed mine several times in the water and while I have a shut off valve, before that I did, as others mentioned just make sure you plug it or lift up the inlet hose and secure it with a line, tie wrap or something to keep it up while you work. You might want to double check your bilge pump is working before starting :)
 
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Thanks for all the advice. Used a wood tapered dowel to plug hose.
Took 2 hrs from start to finish, done!!! Sadly, the old impeller did not look bad. Thus still tracing my overheating problem : (
 
How did the housing look? Don't dismiss it - the tiniest of scratches can do it - if you can feel the scratches with your fingernail, it's too deep. What are your overheating issues... idle... load... speed... etc?
 
I just changed my manifolds and learned the hard way that I needed to plug the hose to the water pump. Access was minimal and extremely difficult to maneuver and get off since you can’t apply a lot of force, but other than thAt, plugging it only takes a few seconds. I used wooden dowlels, and they worked great.
 
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