No water = No good!!!!!!!!

[fogducker III]

I went out Friday for a "shake down" run getting ready for a local Fun Run on Saturday, took an OSO member who was in town with his wife who was on a training course, he had never been here and was looking for a run in a boat so I offered. Had a great day, took my new puppy Donzi out with us and had a good run with no problems, even ran into TWO pods of Killer whales....

Launched early on Sat for the Fun Run, idled out of the bay and the engine temp spikes, shut down and check the engine bay, water in the bilge, check the water lines etc and could not figure out the issue, unhooked the "out" water line from the raw water pump, no water, must be impeller. Floating in the bay and an RCMP Zodiac comes by and kindly offers a tow to the dock. Tie up and start removing the raw water pump, VERY tight location and a PITA to say the least. Got the pump off and find the housing like this.......

Hop in the truck, trailer attached, blast home and grab the replacment housing I just happen to have on the shelf, drive back to the boat and install, check everything over and back on the water in an hour or so.....the rest of the day went well..............:dolphin:

All I can think of is kelp or a plastic bag plugged the water intake and the dry impeller stuck in the housing and the pressure pushed and cracked the housing....???

As they say, "$hit happens..."

[Walt. H.]

I would say more likely raw water w/o antifreeze froze in it during winter storage and cracked the housing when the water turned to ice and expanded, i'm sure it was leaking bad from the crack before it fell apart.

The pump creates more pressure pushing water then then it would if clogged sucking a vacuum, and the impeller doesn't look burned or scored at all if it was running dry.

[fogducker III]

I would say more likely raw water w/o antifreeze froze in it during winter storage and cracked the housing when the water turned to ice and expanded, i'm sure it was leaking bad from the crack before it fell apart.

The pump creates more pressure pushing water then then it would if clogged sucking a vacuum, and the impeller doesn't look burned or scored at all if it was running dry.

Nope, boat stored in heated garage, I replace my impeller at the start of each season. Hard to see in the pic but the impeller was bonded to the housing. The day before the boat ran fine with normal temps and no leaks.

Either plastic or seaweed covered the intake on the leg......:yes:

[Walt. H.]

OK that leaves freezing out but Clogging the intake at the drive is definitely not possible to break the pump like that, but since you said you replaced the impeller is there a chance you might have cracked the pump yourself accidentally during the reassembling or just chalk it up to a manufacturing casting flaw?

[BUIZILLA]

I saw 2 that got so hot they melted the impeller, and distorted the case... in fact, I saw it twice :( :smash: no way an impeller in that good of shape cracked that housing, that was an impeller install issue, or belt too tight, or loose bracket, or ...

[Carl C]

A plastic raw water pump = bad news. Get one of these: http://www.cpperformance.com/p-14544-stainless-steel-lifetime-sea-pump-overhaul-kit.aspx

[fogducker III]

I agree Carl, the plastic housings are crap.

I installed the impeller, done it more then a few times, I have NEVER had any problems and this last install was fine, no leaking from anywhere, including the housing. Good water supply either when flushing or running....I disagree that a dry pump with a rubber impeller starting to heat up could not crack a plastic housing, especially where it did break, the mount is fine, belt tension was fine and as I said, I had a number of hours on this pump with no issues.......manufacturer fault....perhaps......

[silverghost]

Boy~

Don't you just love plastic vital engine parts ?

The only thing worse than a plastic seawater pump housing are the new plastic intake manifolds & timing covers.

[mrfixxall]

i have seen quite a few like this,,usually from water freezing in the housing,from the looks of it its the bottom of the pump and that where the water usually settles..i know you had the engine apart so could the garage have got below freezing when you didn't put wood in the wood stove?

option 2 i have cracked them my self by thinking its tight and giving the bolts a one more time go over and have cracked them..

[Rumblefish]

I saw 2 that got so hot they melted the impeller, and distorted the case... in fact, I saw it twice :( :smash: no way an impeller in that good of shape cracked that housing, that was an impeller install issue, or belt too tight, or loose bracket, or ...

Yes . doesnt apear to have heated as if ran dry for 5-10 second without water...

I would still add a strainer

[fogducker III]

I have an electric oil heater as well as a water bed "mat heater" around the engine so it did NOT freeze. The pump did NOT leak after install nor after running for a number of hours, so it was not over tightened. The cracked area is actually the side of the housing, not top or bottom.

I have a strainer......

Bottom line, the pump didn't get water for a short period of time, heated up and cracked, why? Perhaps a faulty housing from the maker or the impeller bonded to the housing and the torque from the shaft was enough to crack it open.....anyhow, it is fixed and running great.....:)

[MOP]

Those pumps are just plain junk! Notice how nice the impeller looks, it did not suffer lack of water. At work we flip those housing like hot cakes. Merc should be ashamed putting junk out like that!

[Carl C]

Those pumps are just plain junk! Notice how nice the impeller looks, it did not suffer lack of water. At work we flip those housing like hot cakes. Merc should be ashamed putting junk out like that!

I agree. That impeller did not run dry. I ran one dry at the dock once for less than 5 minutes at idle and the edges were burned up.

[fogducker III]

So after receiving all these different opinions I pryed the impeller out of the housing, the first picture, sorry not the best phone/camera pics, shows the end of the impeller that makes contact with the stainless base plate, the other pic is the end that was "welded" to the inside plastic surface of the housing....... I actually cracked the housing even more prying it free....all I can assume is the impeller was spinning inside the housing with no water and the plastic and rubber surface heated up faster then the rubber/stainless surface....?

[BUIZILLA]

isn't that one of those blue run-dry impellers? I think it's mostly a silicone content material?

[fogducker III]

isn't that one of those blue run-dry impellers? I think it's mostly a silicone content material?


As far as I know it is a stock Merc rubber impeller.....:bonk:

[fogducker III]

isn't that one of those blue run-dry impellers? I think it's mostly a silicone content material?


I assume these are what you are refering to? If it was one of these I might not have had the problem...

http://www.globecomposite.com/pages/products_impeller

[mrfixxall]

problem solved!

http://www.cpperformance.com/images/Product/large/625-4178.jpg

[Carl C]

problem solved!

http://www.cpperformance.com/images/Product/large/625-4178.jpg

Yup! Here's mine after I broke off a hose connection prying the hose off my plastic POS. http://i763.photobucket.com/albums/xx275/CARLC222/Pictures144Medium.jpg

[silverghost]

What do these new pump housings sell for ?

Looks like someone found a real need in the aftermarket and filled it.

Indmar was using those dang plastic hose fittings on their manifolds.
Mine shattered like glass when I carefully tried to remove a hose.

No more plastic parts for me.

[mrfixxall]

What do these new pump housings sell for ?

Looks like someone found a real need in the aftermarket and filled it.

Indmar was using those dang plastic hoe fittings on their manifolds.
Mine shattered like glass when I carefully tried to remove a hose.

No more plastic parts for me.


Cp perfprmance. 169.00 for the kit..

[silverghost]

Cp perfprmance. 169.00 for the kit..

Not a bad price at all ~

Considering what a complete new OEM plastic pump , or the replacement plastic pump housing sells for at factory replacment parts prices.

[Walt. H.]

Many years ago when I might rarely screw up :rolleyes: putting something back together at work when I was in my teens and early 20's, I would deny responsibility and try to explain to my boss that it wasn't my fault and he would remind me that the Nile is not just a river in Egypt.
:rofl:
Hey it's hard to admit that we're only human sometimes, but the jury has spoken and agrees with the initial findings that it did not run dry first, so i'll say you're innocent of foul play and the plastic housing became brittle with age and broke on its own and then the impeller spun dry once the pump assembly broken open and no longer could function to suck and push water. :nilly:

[MOP]

I second Walt's appraisal due the fact that there is no rubber burned onto the bore, we get these things in fried and done it. A metal housing unless sand damaged can be cleaned and reused for many years not this junk.

[fogducker III]

Many years ago when I might rarely screw up :rolleyes: putting something back together at work when I was in my teens and early 20's, I would deny responsibility and try to explain to my boss that it wasn't my fault and he would remind me that the Nile is not just a river in Egypt.
:rofl:
Hey it's hard to admit that we're only human sometimes, but the jury has spoken and agrees with the initial findings that it did not run dry first, so i'll say you're innocent of foul play and the plastic housing became brittle with age and broke on its own and then the impeller spun dry once the pump assembly broken open and no longer could function to suck and push water. :nilly:

Walt, don't patronize me....I respect your opinion but you need to practice your delivery.....:yes:

I am not a young, inexperienced noob.....I have been working on marine items of one kind or another for over 30 years, mostly outboard and more recently inboard. No, I am not "trained" nor am I an expert, I do however know a little......:wink:

I did not start this thread for your opinion, I started it to relay an event, a story of something that actually happened. I was there, I know the details and circumstances and have narrowed down the cause to my satisfaction.

As I said, I respect the opinion of members here but I certainly don't expect a "lecture".......and I don't appreciate it.

[Carl C]

Let it go then before it gets ugly. It broke. It doesn't f**kin' matter why. Cute puppy pic BTW.:toilet:

[fogducker III]

Let it go then before it gets ugly. It broke. It doesn't f**kin' matter why. Cute puppy pic BTW.:toilet:
I hear ya Carl, I agree, it broke, I told the story and a few voiced their opinions on why, they did not build the engine or install the NEW pump and were not there when it happened so I find it interesting that they come up with a theory on what caused it.....I just don't appreciate HOW the opinions are voiced at times.......seems to be a pattern on this site at times.....:(

PS. Thanks, the new pup is doing well, went for her first boat ride the other day, she settled in quickly....:)

[Fishermanjm]

Oh yea Carl,,, im ordering one today,,, thanks for that info

[Carl C]

Oh yea Carl,,, im ordering one today,,, thanks for that info

Those pumps are really nice for that price. Hopefully they are still available. You will need to order the fittings too.

[Walt. H.]

Walt, don't patronize me....I respect your opinion but you need to practice your delivery.....:yes:
I am not a young, inexperienced noob.....I have been working on marine items of one kind or another for over 30 years, mostly outboard and more recently inboard. No, I am not "trained" nor am I an expert, I do however know a little......:wink:
I did not start this thread for your opinion, I started it to relay an event, a story of something that actually happened. I was there, I know the details and circumstances and have narrowed down the cause to my satisfaction.
As I said, I respect the opinion of members here but I certainly don't expect a "lecture".......and I don't appreciate it.
Hey Chill' and don't catch a attitude by turning it around to kill the messenger and telling me that I need to learn what ever you meant by delivery?
I at no time did I imply you were a young kid I was referring to myself when I mentioned a teenager, I thought I was talking to a friendly member not someone with a chip on their shoulder with an axe to grind.
I'm sorry to say you've read what I wrote earlier the wrong way by not being able to hear the tone of my voice or see my facial expression as if we were talking face to face, and unfortunately it seems you interpreted all I said ass backwards by your response to me.
If you weren't looking for an opinion or advice to reassure what you thought was the cause, you made a mistake by posting this issue in the first place because from your own experience you had to know you would get members to post exactly what followed and sorry we disagreed.

With that said and seeing your sensitivity evolve through all these replies to myself and others, I will do you and myself a favor and avoid responding to any of your future posts.
It's really a shame when many of us here are glad to give our professional paid years of experience away for free just for the asking, but now may think twice to bother the next time someone looks for a question to be answered.

WH

.

[fogducker III]

Hey Chill' and don't catch a attitude by turning it around to kill the messenger and telling me that I need to learn what ever you meant by delivery?
I at no time did I imply you were a young kid I was referring to myself when I mentioned a teenager, I thought I was talking to a friendly member not someone with a chip on their shoulder with an axe to grind.
I'm sorry to say you've read what I wrote earlier the wrong way by not being able to hear the tone of my voice or see my facial expression as if we were talking face to face, and unfortunately it seems you interpreted all I said ass backwards by your response to me.
If you weren't looking for an opinion or advice to reassure what you thought was the cause, you made a mistake by posting this issue in the first place because from your own experience you had to know you would get members to post exactly what followed and sorry we disagreed.

With that said and seeing your sensitivity evolve through all these replies to myself and others, I will do you and myself a favor and avoid responding to any of your future posts.
It's really a shame when many of us here are glad to give our professional paid years of experience away for free just for the asking, but now may think twice to bother the next time someone looks for a question to be answered.

WH

.


Whatever............I didn't ask for your "paid experience" and I certainly didn't ask for your condescending reply. Your right, replies on here don't come with tone of voice or facial expressions, even more reason to re-read what you type.....:boggled:

You are also right that I should have expected the "regulars" to pipe up with their input when I post, silly me......:bonk:

It was just a story of what happened while out boating one day Walt, nothing more, nothing less.....:)

[Fishermanjm]

how big is lil Donzi these days,,, he or she must have doubled in size by now,,, my golden loves the boat, however she hasn't been out in the donzi yet

[Walt. H.]

F.D.III
It appears you're going to believe what you want no matter what I say, and i'm sorry your feelings were unintentionally hurt or insulted by how you incorrectly interpreted what I wrote.
Maybe it's a regional thing but it was not my intention to cause you to feel I was attempting to belittle you or as you mentioned to cause "the regulars to pipe up" and to explain what they know, I wasn't aware if you're having issues with others.
As a member and like to think of you as family I just didn't want to see you thinking it was a clog that caused your condition.

So I'll leave it at that and wish you All the Best for a good trouble free summer!
WH

[fogducker III]

Walt, I understand where you are coming from and you were just trying to help, like you, I have connections with this site that are beyond just an "internet board".......

I am as guilty as anybody when I post I should sometimes re-read it before I hit "submit reply"....... my responses to you were not regionally inspired, nor were they due to my over senstive nature, ask anybody that knows me, I have skin like an elephant....:tongue:

I believe what I believe and started this post only to relay a story.....

I hope you and yours have a great summer of boating.....:yes:

PS. Just as a side note, this is a VERY interesting read, it would explain the housing failure......

http://en.wikipedia.org/wiki/NPSH

[DonziJon]

That's an interesting article. I'm not sure however that "Cavitation/Vapor Pressure" etc, would explain the housing failure. I would think the flexibility of the rubber vanes would limit the "pressure" that could be generated by the pump vanes....ie.. enough to fracture the housing like that. I don't know what the housing material is but by the way it broke, I suspect it's "Bakelite" which is not very resilient. Same material as some distributer caps. In fact it's brittle and cracks pretty easily.

Is it possable that the housing was torqued down unevenly..causing the fracture...??

One of my jobs was failure analysis when I worked for Brown & Sharpe machine tools back in the 70s. I'm just looking at this as an engineering excercise.. not trying to stir the pot Foggy. DJ

[fogducker III]

That's an interesting article. I'm not sure however that "Cavitation/Vapor Pressure" etc, would explain the housing failure. I would think the flexibility of the rubber vanes would limit the "pressure" that could be generated by the pump vanes....ie.. enough to fracture the housing like that. I don't know what the housing material is but by the way it broke, I suspect it's "Bakelite" which is not very resilient. Same material as some distributer caps. In fact it's brittle and cracks pretty easily.

Is it possable that the housing was torqued down unevenly..causing the fracture...??

One of my jobs was failure analysis when I worked for Brown & Sharpe machine tools back in the 70s. I'm just looking at this as an engineering excercise.. not trying to stir the pot Foggy. DJ

I hear ya, no problems here....interesting thing is, a friend of mine is the manager of the "Refrigeration, Air conditioning etc" for the local Navy Dock Yard and deals with pumps etc on Canadian Navy ships. He contacted me after hearing about my situation and explained it to me in "laymans terms"...basically the small amount of water left in the pump after the intake water is cut off super-heats and can "weld" the rubber and plastic together and with the pump shaft still trying to turn can place a great deal of torque on the housing, which is similar to Bakelite, and could easily crack the housing....end of the day, it is fixed and I will be installing a metal housing with a blue globe run dry impeller in the future....:yes:

[Walt. H.]

NPSH is an initial-ism for > "Net Positive Suction Head".
Oh Boy", I'm usually into all things technical but trying to follow that entire read had me re-reading it back and forth 5-X's until I just said ok? :bonk:
But one thing i'm sure of if I can explain this thought without getting into trouble taking this into a sexual topic and that is, the next time a woman puts a smile on my face i'm afraid the thought of Net Positive Suction Head will cross my mind among other things? :pimptwo::thumbsup:

[Phil S]

At this point, and I'm sorry about this FDIII, because I really couldn't care less what it does to impellers....but I am all about "NPSH" !!!





;)

Glad ya got it sorted out...no matter the cause.......and thank you Walt as well. Explaining the benefits of molten impellers to my wife, however, is another subject altogether. ;)

[Fishermanjm]

FD,,, what is the blue globe run dry impeller? i checked on the SS pump body that carl mentioned, out of stock at the present time, would you replace the entire pump or just the impeller body? I would think that mine is the origional pump, im just thinkin bout the bearing etc...

[silverghost]

Globe/Barco makes a blue colored replacment Impeller (Silicone based?) that is claimed to be able to be run dry for 15 min. wihout burning or melting.
I have used them in the past.
They are quieter than the black rubber OEM units.
They will also not build-up as much water pressure because their vanes are softer.
Some folks have had their center plastic drive hubs tear-loose & fail.
Search Globe Barco Impeller here for older threads & posts.
I never had a issue with the two that we once used.
In fact they lasted much longer than the OEM units for us.