I have watched your video and found it impressive. It clearly shows what can happen when the wear ring wears in such a way. Although I agree with your findings, I don't agree that you have debunked the case drain test. Most piston slippers are brass for protecting the swash plate and the piston ports have brass bushings for protecting the piston barrel from damage. The clearances between the pistons is .0003" to .0004' thousands of an inch. When the brass starts to wear the clearances get larger increasing the opening from pressure port to the pumps case. The slippers have orifices drilled in each one to provide lubrication between the slippers and swash plate. When the brass orifices increase in diameter from wear, you get increased case flow. I have troubleshot hundreds of pumps over the last 35 years in the field some as a Millwright and many more as a Hydraulic Specialist and have found it to be effective in most cases. There are many other ways to troubleshoot pumps as well, I dont just rely on this one test. I will keep teaching and using this technique as a means of testing pumps. I liked your test, but the wear ring is not always going to be the part that fails.
Nice video showing one aspect of wear that occurs in a hydraulic pump (the interface between port plate and barrel). This test is done by any respected pump repair center and is basically industry standard. I think that you have opened a can of worms though by stating that the case drain method has been 'debunked', in certain situations this is the only test that be performed while on the field and does have it's merits. If showed a test with not only a worn barrel and valve plate, but also a piston and swash plate set that have similar hours of operation, you will find a significant increase in case drain flow. Keep up these videos, they are very well made and definitely will help in teaching the concepts of hydraulics that really require visualization.
Your conclusions are completely predictable... so I wonder who decided that monitoring the case drain test would predict anything meaningful as a diagnostic or performance monitor? However, the case flow test will identify leaking pistons against the swash plate which would be seen at the case drain as flow as well as the flow reduction at pressure. Ideally you would have the measured parameters for both case drain & pressure under load because it would allow you to determine which parts (plate or pistons or both) are worn. Known good condition test data would also be valuable for both as well, but this is new system performance data...
![Gucci Mane & Sexyy Red - You Don't Love Me [Official Music Video]](http://i.ytimg.com/vi/j7IBqyFKT4c/mqdefault.jpg)
I have watched your video and found it impressive. It clearly shows what can happen when the wear ring wears in such a way. Although I agree with your findings, I don't agree that you have debunked the case drain test. Most piston slippers are brass for protecting the swash plate and the piston ports have brass bushings for protecting the piston barrel from damage. The clearances between the pistons is .0003" to .0004' thousands of an inch. When the brass starts to wear the clearances get larger increasing the opening from pressure port to the pumps case. The slippers have orifices drilled in each one to provide lubrication between the slippers and swash plate. When the brass orifices increase in diameter from wear, you get increased case flow. I have troubleshot hundreds of pumps over the last 35 years in the field some as a Millwright and many more as a Hydraulic Specialist and have found it to be effective in most cases. There are many other ways to troubleshoot pumps as well, I dont just rely on this one test. I will keep teaching and using this technique as a means of testing pumps. I liked your test, but the wear ring is not always going to be the part that fails.
This video shows real interesthing points.. but.. normally most of pumps if you do a drain leakage test , it will show if the pump is worn.
Nice video showing one aspect of wear that occurs in a hydraulic pump (the interface between port plate and barrel). This test is done by any respected pump repair center and is basically industry standard.
I think that you have opened a can of worms though by stating that the case drain method has been 'debunked', in certain situations this is the only test that be performed while on the field and does have it's merits.
If showed a test with not only a worn barrel and valve plate, but also a piston and swash plate set that have similar hours of operation, you will find a significant increase in case drain flow.
Keep up these videos, they are very well made and definitely will help in teaching the concepts of hydraulics that really require visualization.
Great and insightful video. Gave me a greater understanding of the operating and testing techniques.
Very nice informative video
Super Sache
Your conclusions are completely predictable... so I wonder who decided that monitoring the case drain test would predict anything meaningful as a diagnostic or performance monitor? However, the case flow test will identify leaking pistons against the swash plate which would be seen at the case drain as flow as well as the flow reduction at pressure. Ideally you would have the measured parameters for both case drain & pressure under load because it would allow you to determine which parts (plate or pistons or both) are worn. Known good condition test data would also be valuable for both as well, but this is new system performance data...