Supposed seized water pump bearing

[FrenchFry]

Volvo Penta 5.7 GXI-G 2006

I had a problem this summer (which unfortunately did not turn well at the end due to an unlikely serie of events), while reaching my destination with the boat I slowed down to absorb the wave of a big boat, then accelerating again I heard a strange noise in the engine hatch, I stopped the engine, look at it and saw that all the water hoses were mixed

The water pump did rotate and some people are arguing that this is due to the fact that the water pump bearing got seized

I have a very hard time to believe it, since the engine was running I don't see how the bearing can all of a sudden get blocked and be stronger than the belt so it breaks the water pump support and the whole thing rotates

Has anyone here ever seen/heard of something similar, or does anyone think that this is possible?

Same people argue too that when you change the impeller and/or seals you must change the bearing (true? I don't see it in the Volvo maintenance manuals)

 

[Scott Danforth]

pull the pump and look.

bearings can seize and what breaks is a crap-shoot.

 

[harringtondav]

Volvo Penta 5.7 GXI-G 2006
I stopped the engine, look at it and saw that all the water hoses were mixed

I don't understand "mixed" water hoses. Please explain the condition in more detail. Thx.

 

[FrenchFry]

The water hoses were tangled (because the water pump did rotate)

Not sure what means "crap-shoot"

"pull the pump and look" --> the boat did sink at the end, not because of this, things are now solved with the insurance, but could not have, because the insurance "expert" did put everything on my back, to conclude absurd things from my standpoint (and now that the water pump has been removed after one week in salt water without me being there, it's difficult to see what happened)

Like "this is a typical case of water pump seized bearing", I don't believe that this is "typical", usually the belt slips on the pulley if this happens, and I don't believe that it can happen all of sudden like this, when the bearing is not far from seizing you can detect it

That's what I am asking here, if someone knows about a water pump rotation possibility because of this, googling it I have found just zero cases

 

[Maclin]

Not any kind of expert here, but just my 2cents, the pump bearing is not usually on any service schedule. Not something you could check before going out even if you wanted to. A failure like this would not be from lack of maintenance in my opinion, unless it had been making noise for a while before this on other trips and was ignored.

 

[Scott Danforth]

Not sure what means "crap-shoot"

bearing failure is not common. however it usually starts to make noise long before it would seize. however if it does seize, maybe the belt slips, maybe the shaft breaks, maybe the brackets break..... there is no definative mode of failure

"pull the pump and look" --> the boat did sink at the end, not because of this, things are now solved with the insurance, but could not have, because the insurance "expert" did put everything on my back, to conclude absurd things from my standpoint (and now that the water pump has been removed after one week in salt water without me being there, it's difficult to see what happened)

sounds like the pump is the least of your issues. a week in salt water and every wire/switch/piece of electronics will be junk.

 

[FrenchFry]

sounds like the pump is the least of your issues. a week in salt water and every wire/switch/piece of electronics will be junk.

Yes, as I said things are now OK with the insurance, but this "expert" wrote so many bulls in his report (misleading the insurance so I was supposed to get nothing, that's not the purpose of this thread but I know why he did this) that I still want to demonstrate that everything is false, like there is nothing typical in his "this is a typical case of water pump seized bearing", or "when you do a corrective change for the seals you change the bearing also"

So thanks all of you for the answers, others are welcome (again I can't find at all a similar case)

 

[Thalasso]

Would still like to know what you mean by all the water hoses were mixed

 

[kenny nunez]

Is your water pump driven from the crank shaft nose or is it belt driven? Do you have any pictures?
Any time I had to write a insurance claim for my customers I made sure that they got well compensated and the adjuster understood the claim.

 

[FrenchFry]

Would still like to know what you mean by all the water hoses were mixed

"tangled" not "mixed" in fact, the water pump turned then the water hoses connected to it did the same

Is your water pump driven from the crank shaft nose or is it belt driven? Do you have any pictures?
Any time I had to write a insurance claim for my customers I made sure that they got well compensated and the adjuster understood the claim.

Belt driven

Let's forget about the insurance, I just would like to know what people think from a technical standpoint of "this is a typical case of water pump seized bearing" and "when you do a corrective change for the seals you change the bearing also"

 

[Horigan]

Scott's response is the best. There is no typical failure mode. It would be one of three he listed; slipping belt, broken shaft, or twisted bracket, which you experienced.

 

[Fishhead-1]

The pump is crankshaft driven, not from the belt. Of coarse the pump assembly will try to spin if the bearing seizes. The bracket is there to hold the pump from rotating and pulling on the hoses. When servicing impeller you can rotate bearing housing to feel if rough or Noisey. Like Scott said before failure it must have been making noise along time.

 

[FrenchFry]

Yes, it was not making noise at all, I did change the seals and it was rotating perfectly

So does someone think here that the theory of the "expert" saying that it can get seized and rotate all of a sudden at sea when the engine is running is plausible?

As well as the assumption that it is mandatory to change the bearing each time you service the water pump?

 

[Scott Danforth]

If your seal was bad, its good mechanical practice to change the bearing.

and yes, if the bearing seized, it would have been making noise for a while, then all of a sudden when the bearing gets hot enuigh to weld the balls to the races, the pump may spin.

We have answered your question adnauseum

 

[FrenchFry]

OK thanks