I have a Bradco model 8511X and I blew out the back end of the hydrolic swing cylinder. My guess it was form meatal fatigue. However I though I would check with the form and see if their is anything else I should be checking with the system. Thanks John
Blew out the back end of a hydrolic cylinder
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Dave M7040
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In looking at a picture on line I wanted to be certain I knew what cylinder you are talking about.
Metal fatigue in the end of a hydraulic cylinder is very, very unusual.
It could happen if the pivot arrangement at either end of the cylinder is seized and then the cylinder is seeing bending loads it was never designed for.
Post some pictures.
Read this article on pressure intensification in hydraulic cylinders.
Pressure intensification in hydraulic cylinders
Dave M7040
Yes that is the exact cylinder that failed. It blew the end closest to the tractor. (opposite end of the cylinder as shown). I have the cylinder out of the machine. I will post phots next week. We did not noticed a bent rod but I will check. I have the service manual for the machine and I review/try to figure out where and how to got a pressure reading.
I have called my dealer to get parts and should know Monday Tuesday this week
Thank you all for your comments and I will keep you posted on progress. Thanks John
I have called my dealer to get parts and should know Monday Tuesday this week
Thank you all for your comments and I will keep you posted on progress. Thanks John
Dave M7040
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John
Yes plse let us know the outcome of this as we all learn.
Since my earlier post I have been doing more reading.
You should be looking for a crushed steel hydraulic pipe if there are any and also a quick coupling that does not seat properly.
A flow restriction on the rod side of the cylinder will cause the intensification.
In the case of your swing cylinders, in my mind this is a different application than say a Front end loader. On the FEL both arm cylinders or both bucket cylinders are both working together to lift the load or roll the bucket back.
In the situation shown by the photo I posted, you have two cylinders perhaps fighting each other. When one wants to extend the other has to retract. This is a much different application.
Are the swing cylinders double acting, i.e. two hose connections, or single acting?
Dave M7040
bigdeano
Platinum Member
Swinging the backhoe rapidly and suddenly closing the valve would cause a pressure spike. Some hoes have pressure relief valves on the swing to prevent damage. If you swing all the way to the side does the cylinder stop the swing, or is there a separate stop?
This is the phots I took today. As you see the end is blown out. I think the rod is bent because I can not move the rod at all. As I look at the front end it seems to be bent when I look at it in relationship to the end cap. Later this week I am going to try to take the nut off and see if I can get the shaft out to see how it looks.
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Dave M7040
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Can you help me with understanding your photos.
The large nut in the second photo is the nut connecting the push rod to the piston inside the cylinder?
How does the cylinder come apart. Does the end of the cylinder near the push rod eye unscrew?
Or, was the end of the cylinder that blew off, secured with a large snap ring. I think I am seeing signs of a groove for the snap ring where the cylinder failed.
Dave M7040
The large nut in the second photo is the nut connecting the push rod to the piston inside the cylinder?
How does the cylinder come apart. Does the end of the cylinder near the push rod eye unscrew?
Or, was the end of the cylinder that blew off, secured with a large snap ring. I think I am seeing signs of a groove for the snap ring where the cylinder failed.
Dave M7040
