Water pump failure, may have ruined block!
#167
I have never once before today heard of "package migration" ... all the failures I have seen, have happened as a result of what you might call "package failure". In other words the contents of the bearing/shaft unit were damaged inside.
#170
Awesome H and thanks for that.
The failure I just reviewed is a Porsche rebuilt pump from 928 Int (Extremely Reputable Supplier) and the seal cartridge has come out of the casting exactly how Laso said it would.
Jim & Bill,
I thought I was getting somewhere with this but you have different ideas so maybe you would like to lead the challenge to find a fix!!! I will leave it for a couple of weeks and see what you come up with 8>)
Roger
The failure I just reviewed is a Porsche rebuilt pump from 928 Int (Extremely Reputable Supplier) and the seal cartridge has come out of the casting exactly how Laso said it would.
Jim & Bill,
I thought I was getting somewhere with this but you have different ideas so maybe you would like to lead the challenge to find a fix!!! I will leave it for a couple of weeks and see what you come up with 8>)
Roger
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
#171
Roger this quest has taken me a decade. So ,... please don't let me discourage you. I do not mean to poo-poo your efforts at all, just to add info!!! Yes I had an Intl pump fail also ... the one on the mis-timed engine .. it failed by leaking coolant.
#172
Well this has remained dormant for the last couple of weeks while I got rusty in the UK 8>)
Talked this through with a lot of engineers and we have a number of thoughts to follow up on.
Both the Laso & Porsche castings seem to be exactly the same material. I will do some measurements of the bore to try and get a benchmark size for comparison. By far the biggest failure mode is the movement of the sealing cartridge within the bore of the casting. I finally received a call from GPM and they are willing to talk to me about the issue. Hopefully later this week we can have some input from them as well.
The second failure mode - very small percentage - is the impeller coming off the shaft. The seal cartridge is replaced so we know the shaft diameter should be new and not degraded by reuse. However is the impeller new as well or is it reused after a clean. Same goes for the pulley. My gut tells me that this failure mode would cause little damage. For the impeller to come of the shaft means it is spinning freely and as such would not cut into the block with any serious damage. THOUGHTS ON THIS PLEASE?
By far the most used WP is the rebuilt WP. I sell a lot every year, 928 Int must sell 10 times that amount.
The rebuilders are always short of cores to rebuild, that is why there is a core charge.
How many times is a core being reused??? I suspect many times and this will result in the bore of the casting being changed.
Talked this through with a lot of engineers and we have a number of thoughts to follow up on.
Both the Laso & Porsche castings seem to be exactly the same material. I will do some measurements of the bore to try and get a benchmark size for comparison. By far the biggest failure mode is the movement of the sealing cartridge within the bore of the casting. I finally received a call from GPM and they are willing to talk to me about the issue. Hopefully later this week we can have some input from them as well.
The second failure mode - very small percentage - is the impeller coming off the shaft. The seal cartridge is replaced so we know the shaft diameter should be new and not degraded by reuse. However is the impeller new as well or is it reused after a clean. Same goes for the pulley. My gut tells me that this failure mode would cause little damage. For the impeller to come of the shaft means it is spinning freely and as such would not cut into the block with any serious damage. THOUGHTS ON THIS PLEASE?
By far the most used WP is the rebuilt WP. I sell a lot every year, 928 Int must sell 10 times that amount.
The rebuilders are always short of cores to rebuild, that is why there is a core charge.
How many times is a core being reused??? I suspect many times and this will result in the bore of the casting being changed.
#173
Roger I have not seen a failure of the package moving in the bore. If you look at the failed LASO in my pic, you see the package is in-place and the bearings disintegrated inside, allowing the shaft to move axially, causing the impeller to dig into the casing .... that failure is what I have seen very often. Not just on Laso.
In fact, on many the failure is a GRINDING PUMP BEARING ... this cannot be the result of a moving package. Also, when coolant leaks from the front of the pump, this cannot be a result of a moving package. ... rahter when a pump leaks, it leaks at the shaft. That means coolant got past the shaft/bearing/seal.
As stated, the pump you see there had bearing bits fall out when I pulled it out.
In fact, on many the failure is a GRINDING PUMP BEARING ... this cannot be the result of a moving package. Also, when coolant leaks from the front of the pump, this cannot be a result of a moving package. ... rahter when a pump leaks, it leaks at the shaft. That means coolant got past the shaft/bearing/seal.
As stated, the pump you see there had bearing bits fall out when I pulled it out.
#174
H,
I am basing the questions on the failures that have been reported. By far the most failures have been the seal cartridge moving in the bore. These are all fairly current failures.
Your failure of the bearings is the only one I have documented. Hence not high on my list.
If there is a problem with the bearings within the seal cartridge we would have to locate the manufacturer and define which is good and which is bad. You say you know of other failures of the bearings - any documentation, numbers, dates?
I may find that in my discussions with GMB and Laso.
Roger
I am basing the questions on the failures that have been reported. By far the most failures have been the seal cartridge moving in the bore. These are all fairly current failures.
Your failure of the bearings is the only one I have documented. Hence not high on my list.
If there is a problem with the bearings within the seal cartridge we would have to locate the manufacturer and define which is good and which is bad. You say you know of other failures of the bearings - any documentation, numbers, dates?
I may find that in my discussions with GMB and Laso.
Roger
#175
Roger tin that case IMHO you're chasing wind. If you've ever heard of a leaky water pump, then you've heard of a failure inside the cartridge. Because a cartridge moving cannot leak. And if you've ever seen a propeller come off or move, then that has nothing to do with a moving cartridge.
Who reported the moving cartridges as a failure? Never have heard of one.
My GTS' belt failed twice partially as a result of a perfect pump with a grinding bearing. Package is perfect.
Godzilla's pump failed a few weeks ago ... low miles .... 20k. Leaks at the shaft.
My 85 Euro ... leaked at the shaft as a result of overtension. Package in place.
Who reported the moving cartridges as a failure? Never have heard of one.
My GTS' belt failed twice partially as a result of a perfect pump with a grinding bearing. Package is perfect.
Godzilla's pump failed a few weeks ago ... low miles .... 20k. Leaks at the shaft.
My 85 Euro ... leaked at the shaft as a result of overtension. Package in place.
#176
H,
My failure of a 928 INTL rebuilt with only a SITM trip on it (1000 miles) was due to the moving cartridge. This failure was the post that restarted this thread a few weeks ago. I sent this failure to Roger before sending it back to 928 under warranty. He has documented it first hand. The cartridge migrated toward the block thus making a mess between the impeller and my block. the only thing that stopped it was the belt pulley on the WP started grinding on the WP core itself. I was not the only one that this has happened to come to find out...
My failure of a 928 INTL rebuilt with only a SITM trip on it (1000 miles) was due to the moving cartridge. This failure was the post that restarted this thread a few weeks ago. I sent this failure to Roger before sending it back to 928 under warranty. He has documented it first hand. The cartridge migrated toward the block thus making a mess between the impeller and my block. the only thing that stopped it was the belt pulley on the WP started grinding on the WP core itself. I was not the only one that this has happened to come to find out...
#178
H,
All the current failures are directly related to the Seal Cartridges moving. This thread and the other threads. I have searched all of Rennlist and so far have only found other failures associated with the impeller moving on the shaft and in some of those failures it was possibly the cartridge moving. The cartridge moving also makes it look like the impeller has come off the shaft.
Yours was the first where the guts of the cartridge has failed.
I am only working with documented failures.
If you have more throw them in the ring 8>)
Roger
All the current failures are directly related to the Seal Cartridges moving. This thread and the other threads. I have searched all of Rennlist and so far have only found other failures associated with the impeller moving on the shaft and in some of those failures it was possibly the cartridge moving. The cartridge moving also makes it look like the impeller has come off the shaft.
Yours was the first where the guts of the cartridge has failed.
I am only working with documented failures.
If you have more throw them in the ring 8>)
Roger
Last edited by ROG100; 07-21-2008 at 03:22 PM.
#179
However is the impeller new as well or is it reused after a clean.
#180
Rog,
I have my pump boxed with your address label on it. I've been out of town for work with no time to deal with this. However, when you receive my pump you will note my pump failed in the mannor discribed by Heinrich. My cartridge is as it was installed and has not moved, the impeller and pulley are as installed on the shaft, however the shaft is moved back and the impeller ground my block.
BTW: the pump still spins fine and the impeller is square with the pump body. No crooked or tipped shaft or side play.
I have my pump boxed with your address label on it. I've been out of town for work with no time to deal with this. However, when you receive my pump you will note my pump failed in the mannor discribed by Heinrich. My cartridge is as it was installed and has not moved, the impeller and pulley are as installed on the shaft, however the shaft is moved back and the impeller ground my block.
BTW: the pump still spins fine and the impeller is square with the pump body. No crooked or tipped shaft or side play.