wow good thing you weren't tinkering with the engine at the time.think about my flex fan every time i do.

 

Corvette God letting you know you need to drive it more

I've seen many a water pump fail in my 45 years of wrenching on cars but have never seen one fail like that.

I believe you are fortunate. That failure looks like the results could have been much worse.

 

Gives one something to think about when leaning over the fender with a timing light while the engine is racing towards the "all in" rpm.

 

I once saw a heating pump casing split like that, it was chalked up to a casting flaw ... any evidence of that in the casing?

Dave

 

Wow - I have never seen anything like that before. Luckily - no major damage done.

 

I saw your post and got that sick feeling in my gut that comes when these things happen to me. I feel your pain. Best to walk away, cool heads prevail.

I would have thought that a seized impeller would have made the belts slip and squeal like crazy, but snap the housing is hard to imagine. I think you unfortunately have a bad casting there. NAPA needs to see this.
I have no question about where it could have been manufactured, the grain on the casting looks very porous.

Sorry to hear this, and good you had it happen in the garage, better than on the road although cleaning up the anti-freeze is always fun. Don't ask me how I know.

David

 

Holy cow I have NEVER seen a wp failure of that nature. Thankfully you were at home and not moving!

Baffled,

Lee

 

Well, I got it off and there's nothing obvious as to the cause. It looks like it just broke! As some have mentioned, if the bearing seized I think I would have heard some belt squeaking before the break which I didn't? I'll add the pictures I took of it after I got it off and took the rear cover off of it. The something getting in the impeller theory isn't playing out. The inside of the pump looks good and the only sings of the impeller hitting something is right on the edge and after moving it around a bit, those marks appear to have been a result of the impeller stopping on the side of the pump AFTER it broke. The shaft still turns but it is NOT turning freely as it was new. It has a definite rigid turning effort but isn't completely seized. The shaft and bearing assembly is about a 1/4" in towards the back of the pump. But that too may have happened after the breakage because there's no markings on the rear pump cover.Please let me know what you think and if you see anything I'm not in the pictures.

 

Wow, That's just nasty. Like others have mentioned, I've never really seen any water pump fail like that.

In that 3rd pic, it almost appears that the force on the pulley was "pulled forward" (or pushed out from within the pump ... if that makes sense). I vote for a flaw in the casting though. Looking at the body of the pump (where the crack is), it looks almost like there was weak point/flaw somewhere around the weep hole area and the rotation of the fan just "pulled the center out". (kind of like if you attached a dent puller to one of the bolt holes for the fan and and slammed the weight back)..

Just a guess obviously, I'm no engineer, but very nasty just the same. As others have said, glad it was in the garage / not on the road (and your body wasn't anywhere near it...

 

Very cool .............
Yes I have seen this before, However on tractors.
When the belt is installed with half up side down and the other half normal, The tension as the belt is rotated increases The ''wiggle'' if you will, at the weakest polar point. In this case the water pump.
Reason # 18 why serpentine belt/idler are standard equp now.
Sorry, not covered under warranty.
Think of this as wiggleing a piece of wire till it breaks.
Hang this one on the wall....
Ramair.

 

Usually the shaft sheers off.....this is a first for me too.

Jebby

 

Not saying this is what did it but I recall my pos beater that I used for work when I had the nightclub, a 76 or was it 77 mustang 2 with the 302, well after I got the ac working the pulley on the water pump broke where the bolt holes are, being this car make model and 302 even then it wasn't easy to find the correct pulley in the bone yard and I busted a second one...getting worried I knew of a rather savvy mech who mostly worked on situations of hard to cool cars,
He had me bring it in and decided that an idle pulley or smog pump some extra pulley was missing and in turn the belts were pulling harder in one direction on the pulley...he redid the alt and balanced the pull from different directions on the pulley and the third one didn't break...my dad a Navy plane tech rip always scoffed at this but never had a reason it fixed it..

Another situation of oddity,
This was before I could hop on the net and ask a zillion people what they thought,
I was getting a vw trike running, the engine was a mess but I wanted to just see if it would run and I did get it running, it has one belt from crank to gen, I would take off down the street and it would toss the crank pulley off like king kong threw it, it went sailing up between two houses I got way lucky it didn't hit anything, the crank nut and lock washer were good and to torque, and of course went sailing too.

I tried it a second time this time idling do an area where nothing and no one would get hurt, it tossed it off again this time running the pulley, So I hunted down this vw expert, a fellow in his mid 80's who still worked on ACVW's 5 days a week, he chuckled and said, your crank is out of balance likely warped a hair too....he said that sets up harmonics that while it seems to run okay at a certain rpm it will go nuts and in this case toss the crank pulley,

None of that really helps, but this thread made me recall it....

 

Mystery solved!!!

 

China . . ., Who could have expected such a thing??? !!!!!!!

 

My 1995 Oldsmobile Silhouette...AKA "the pregnant Corvette", had the water pump pulley break apart from it's bolted center section, about three years ago. I never saw anything like that happening before. It's a 3.8 liter engine, only had about 69,000 miles on it then. Lou.

 

Hi Jason, like you said at the start so much for getting motivated. I am also selling my home and have often had to force myself from going into the garage to do some work when I am not really into it. I can screw up things when I am into it. I have not seen that happen and I feel for you buddy. Whats next another china beauty of find a GM one?
RVZIO

 

I have to tell you that another look at the fracture surface in the water pump housing has me concerned. Unless it is an anomaly of the photo (flash), it appears that the coloration of the casting surface is pretty dark and changes to lighter in areas. That would indicate to me that the iron material used to make that casting was contaminated in some way and was likely very weak. If the front bearing wasn't seized, I'm suspecting just bad cast iron used for that pump housing.

Should that be the case, send the broken casting back to the vendor and DEMAND your money back.

 

Selling houses, moving, buying houses...no one warned me the ordeal it is,
I lived in the same joint over 45 years, our property had gone way up and I wanted out a little less city and something bigger, my wife jumped on the whole thing and she is very tenacious, she got our house/lot sold as a tear down for more than the joint we bought which is about 5 times bigger...she did this all in about a month signing off on both same week....but the move...geez...3 ratpaks 5 20 ft truck loads just over three months here, I have learned how to install sub panels, do all kinds of plumbing, I had no idea we had so much junk and I still am not settled down.

 

"The good stuff" right. Glad it didn't cause a lot of damage

 

Thought the front page would benefit from this cautionary tale too...
https://www.corvetteforum.com/articl...y-cheap-parts/