View Full Version : water pump impeller help!

09-26-2010, 12:59 PM
first let me say im no mechanic. 454mpi 1999 few weeks ago water impeller went out, which was 2yrs old and i was about to replace. So i put new one in, put on hose ,work perfect! went to lake ran 20 miles no problem, next day no problem. Bring home ,put on hose, no water. So i change again, took oil cooler hose off thermostat housing and back flushed. put a new one in and ran on hose twice and all looked good. Ran yesterday about 30 miles, temp was the usuall 180 and ran great. Well just put on hose to flush and no water again! Any thoughts? the oilcooler strainer clogged is one friends guess? thanks!

09-26-2010, 02:18 PM
How are you putting it on the hose"?
There've been a number of examples of muffs not fitting properly.

09-26-2010, 02:52 PM
the muffs that have the rod that goes thru the drive, seems like a tight fit! Have used them for yrs with no problem. george , what about oil cooler?

09-26-2010, 03:52 PM
the muffs that have the rod that goes thru the drive, seems like a tight fit! Have used them for yrs with no problem. george , what about oil cooler?

No way to know unless you check,
but if it runs in the water but not on a hose, I would suspect the hose arrangement.
You may have noticed many Classics have a transom mounted hose adapter. It utilizes an internal plastic check valve arrangement on the inside supply hose.
This may be something to consider if the muffs prove to be problematic.

09-26-2010, 04:22 PM
ooooh, forget about the muffs!!!! I thought mine have a tight fit but no water came out of the exhaust, arranged the muffs two or three times, still no water. Stopped the engine, looked, turned engine on again and suddenly it worked. The muffs sometimes cause an air bubble or other trouble with the bravo. I had this issue several times, they sometimes work and sometimes don't, so I decided not to use the muffs anymore- they ruin the impeller. This was definitely the problem, no problems in the river at all. I will soon install an extra hose with a valve and hose fitting for flushing my engine.

09-26-2010, 05:30 PM
Are you running with the drive down.Do you have the muffs that water comes from both sides or one side.

09-26-2010, 06:11 PM
Drives down , single water intake. Its the kind that is suppossed to be for bravos...so i was told. Have used the same muffs for yrs with never a problem. Any views on the oil cooler screen clogged with impeller parts and causing problem? mr. fixall or jamie , have a view?

09-26-2010, 08:19 PM
If the drive is up it only takes a few minutes to start to chew the impeller.I have done it my self were i have started the motor up with the drive up and no water coming out .put down and the water runs within sec.from my experience.

09-27-2010, 08:07 AM
you said you back washed the system and obviously know it is important that you back wash all the hoses to get out any impellor parts that may have broken off and run into the system

if they are floating around in there it could cause some issues

pull your hoses wash them out and look for parts

next one you replace "reassemble" it outside of the boat to make sure you have everything (put the rubber thing back together) and you will know if you have everything out

09-27-2010, 09:45 AM
It is hard to say without seeing what you are doing and experienceing for myself in person..

But here are a few things....

If you have a dual water pick up bravo and you are using the attachment that you have, you must block off the low water pick up portion of that.. (although I think you said you may have the single water pick up)..

Rechecking the cooler for blocked passages is fine, however it may not be the problem.

Recheck your strainer set up & inline flush set up of it is so equipped.

Also check to see if the intake hose for your impeller is sucking in on itself or collapsing. If you are running it on a garden hose, it may not be providing enough flow and volume for the impeller pump. It can happen if the intake hose is weak or oil soaked. You may also want to pull it off & check inside to see if it is coming apart inside or collapsing internally..

:) Jamie / Lakeside

09-27-2010, 12:02 PM
I experienced a similar problem. I find the seal between the flush connector (muffs) and water inlet is *critical*.

With the low-water pickup of the Mercury Promax 225X on my Donzi, I duct-tape the flush fitting onto a dry water pickup, sealing every water-pressure escape route possible. Then, I turn on the water and start the motor, flushing (or running) on garden-hose pressure fine. The 225X uses two thermostats, so I must wait until the motor reaches 140 degrees for them to open, and the peeing to begin. During this waiting period, I watch the water-pressure gauge carefully for insurance. It took me some experimentation to determine this flush-fitting-to-water-inlet seal was the root problem.

Now, it works fine every time. Without the tape, the motor merely goes onto the warning buzzer and only a few drops of steamy water exit the cooling indicator. Five or ten cents worth of duct tape goes a long way toward preventing aggravation.

The 120 Force on my Stingray uses a conventional water pickup (above the nose cone). I had problems with inexpensive round muffs. Instead, I bought the upgraded rectangular muffs. These worked, however they have a tendency to walk off when I turn my back! So I drilled them and run a long, small bolt through the muffs and hollow water pickup to hold it in place while flushing with water pressure. This also works well.

Hope this helps,
Andy DiSario

09-27-2010, 08:02 PM
just wanted to say THANKS for all replies! Did take pump off today and impeller is missing plenty of fins. Having trouble taking the hose off the oil cooler ,then ran out of light. Im sure its packed with rubber, will attemp again tomorrow.

09-27-2010, 08:52 PM
While you're in there, why don't you install a hose adapter into the supply hose?
Make things a lot simpler down the road.

09-27-2010, 09:52 PM
george, im definitely going to do that! thanks