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WaterDR

Water Pump Maint

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Alpha`s  every 2 years

Alpha GEN II  3 maybe 4 years

Bravo 3-4 years

At any time the temp rises for no apparent reason

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Impellers seem cheap and doesn’t look that hard.  Looks like an entire kit is $100. Maybe 1 to 2 hours.

not sure why a friend paid $1000 on his.  I suspect there is more to his story 

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8 hours ago, WaterDR said:

Thanks!  I don’t know when it was last done.  Temps are great though.

One simple grounding where some sand was ingested, or running over a floating trash bag, even for a few seconds will trash a brand new impeller. Use of the cheap RV antifreeze for winterization hill stiffen a new impeller also. I put a gauge in my discharge circuit where I can monitor pump pressure in real time. At the very least every 4 seasons or 300 hours on a fresh water Bravo.  W

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Love the gauge idea either pressure or flow.  I also see someone making a stainless pump housing too.

I assume most of you who change annually simply pull out the impeller.  And those who wait longer, replace the plastic housing and buy a kit?

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Here is my tip for extending your pump life, especially for VP owners. When winterizing, I remove the impeller from the pump housing and keep it stored in a bag coated with glycerin during the winter. It keeps the rubber pliable and allows the vanes to "stretch out" during storage. I have two impellers that I rotate into service this way.

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2 hours ago, WaterDR said:

Love the gauge idea either pressure or flow.  I also see someone making a stainless pump housing too.

I assume most of you who change annually simply pull out the impeller.  And those who wait longer, replace the plastic housing and buy a kit?

The Bravo's are solid brass housings and expensive. Covers area bit of a pain to pull for inspection also. The gauge for me is piece of mind and it will show slight, continuous reduction in pressure over time as impeller approaches the end of it's service life. The ECM also has data on sea water pressure in digital representation, but Chap owners cannot see it without a scan tool. Sea Ray owners can see it on their Smart Craft display. I smell a Brunswick Rat... W

http://s526.photobucket.com/user/wingnutmfs/media/BoatDump/Raw water gauge_zpshjkc1z3x.jpg.html

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3 hours ago, Wingnut said:

The Bravo's are solid brass housings and expensive. Covers area bit of a pain to pull for inspection also. The gauge for me is piece of mind and it will show slight, continuous reduction in pressure over time as impeller approaches the end of it's service life. The ECM also has data on sea water pressure in digital representation, but Chap owners cannot see it without a scan tool. Sea Ray owners can see it on their Smart Craft display. I smell a Brunswick Rat... W

http://s526.photobucket.com/user/wingnutmfs/media/BoatDump/Raw water gauge_zpshjkc1z3x.jpg.html

Wingnut-

Can you give more detail on your gauge install?  I think this is a great idea and would like to add it to mine.  '04 350 MPI B3

BC.

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4 minutes ago, bcboater said:

Wingnut-

Can you give more detail on your gauge install?  I think this is a great idea and would like to add it to mine.  '04 350 MPI B3

BC.

Easy addition really. Follow the discharge piping from the raw water pump to the rear of the engine and just behind the intake manifold on the starboard side you will come upon the power steering cooler. On the water side of that exchanger, you will find the Smart Craft raw water pressure sender, and by removing it, you will have a tie-in point for your gauge. Simply install a threaded brass close nipple, a tee, and then re-install the sender into one branch of the tee. The other branch gets a hose barb and a length of flexible reinforced hose suitable for cold water service. To the hose end, mount a quality 0-15# liquid filled gauge that includes over pressure protection. At a given RPM, say 1,500 mark the gauge face with a permanent marker and that becomes your base line reference. Monitor the gauge at 1,500 rpm monthly at a minimum, and you will be able to react to any subtle decline in pump performance. The only catch 22 is the fact that if you were to partially plug the inlet of your main raw water heat exchanger then the pump back pressure would actually increase, but that would be yet another indication of a raw water cooling circuit problem. All good information to have. The key is watching for constant, repeatable pressure at 1,500 and reacting to change.    W

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23 hours ago, Wingnut said:

Easy addition really. Follow the discharge piping from the raw water pump to the rear of the engine and just behind the intake manifold on the starboard side you will come upon the power steering cooler. On the water side of that exchanger, you will find the Smart Craft raw water pressure sender, and by removing it, you will have a tie-in point for your gauge. Simply install a threaded brass close nipple, a tee, and then re-install the sender into one branch of the tee. The other branch gets a hose barb and a length of flexible reinforced hose suitable for cold water service. To the hose end, mount a quality 0-15# liquid filled gauge that includes over pressure protection. At a given RPM, say 1,500 mark the gauge face with a permanent marker and that becomes your base line reference. Monitor the gauge at 1,500 rpm monthly at a minimum, and you will be able to react to any subtle decline in pump performance. The only catch 22 is the fact that if you were to partially plug the inlet of your main raw water heat exchanger then the pump back pressure would actually increase, but that would be yet another indication of a raw water cooling circuit problem. All good information to have. The key is watching for constant, repeatable pressure at 1,500 and reacting to change.    W

Thanks Wingnut - Do you happen to remember the sizes of the fittings & hose?  How did you anchor the gauge?

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not saying this is right, just saying. I would not follow this, I dont follow this either. My buddy just sold his 94 blue water mirage, it had the original impellor. V6 and Alpha One. Believe it or not.

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I never changed my 2002 Merc 5.0L stern drive water pump parts. Until 2015. When I backed into a sandy spot.  Oh Well

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5 hours ago, bcboater said:

Thanks Wingnut - Do you happen to remember the sizes of the fittings & hose?  How did you anchor the gauge?

1/4" NPT on the fittings, and I made a gauge mount from a piece of lite gauge stainless angle. Take a look at SPAN gauges out of Plano Texas. Poly-carbonate gauge bodies, 2-1/2" display face, over-pressure protected and liquid filled.  W

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1 hour ago, jimmerheck said:

not saying this is right, just saying. I would not follow this, I dont follow this either. My buddy just sold his 94 blue water mirage, it had the original impellor. V6 and Alpha One. Believe it or not.

Different animal as the Alphas are flooded suction as they are at or below the waterline, and prime as soon as they begin to turn. The Bravo's and Volvo's run dry for a time until they displace the air in their suction network. A big block engine is thirsty when it comes to cooling water and if you push these belt driven remote mounted pumps past 4 seasons, or 300 hours, you will begin to see temperatures rise both during and immediately after hard runs. Just because the engine coolant temperature sender/gauge is not indicating an issue, does not mean that the exhaust hoses and anti-reversion flappers are not being abused. W

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Thanks Wingnut.  Where did you mount the gauge?  The pic is hard to tell

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I'm sorry Wingnut, I was not meaning to say I wouldnt follow your gauge install, it sounds like a great idea, what I meant to say was this: "my buddy did not replace his impeller from the time he bought his new 94 Blue Water Mirage with an alpha, he never changed the impeller, ever". I do not agree with this, just wanted folks to know sometimes they last a long time. I plan on changing mine every 3 years just to be safe. 

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18 hours ago, bcboater said:

Thanks Wingnut.  Where did you mount the gauge?  The pic is hard to tell

Atop the starboard side exhaust riser. Easy to read from the helm with the engine hatch raised.  W

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15 hours ago, jimmerheck said:

I'm sorry Wingnut, I was not meaning to say I wouldnt follow your gauge install, it sounds like a great idea, what I meant to say was this: "my buddy did not replace his impeller from the time he bought his new 94 Blue Water Mirage with an alpha, he never changed the impeller, ever". I do not agree with this, just wanted folks to know sometimes they last a long time. I plan on changing mine every 3 years just to be safe. 

Yea the old Alphas will hang in there as they spend their life submerged during start-up. They even prime instantly on muffs. A Bravo toward the end of it's service life can take over 5 seconds to prime, and each time that happens the impeller takes an additional hit. I always wondered why the Bravo drives did not have the pump slapped on the back of the upper gear case.  W

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