Continuous Bursting Hydraulic Line

[Doug Weigle]

I have a Case 580 B backhoe. And I need some help. As part of the valve nest under the (backhoe) valve nest (in the rear) there is a hydraulic return line that comes off the valve nest on the left side, and attaches to the return line, which exits under the valve nest through the wall on the right side of the machine. There are two steel lines, 1: off the far left side of the valve nest and 2: the return line that exits the casing below the valve nest through the right wall of the machine (reference sitting facing forward) which are tied together with a 1" rubber hose...not a steel wire cased hose. There is not much pressure in this return line as it appears to be a drain line. With that said, I continuously am "bursting" this rubber tie line, (at least six times so far) which then dumps most of my hydraulic fluid. The routine is the same: I use the "Hoe" section of the machine to dig out stumps, etc...and after a few weeks of use, this hose ruptures. The manufacturer who I buy the replacement 1" hose off of (less than 6" long) tells me the failed hoses rupture from the inside out, because of internal pressure. Interesting that a low pressure whose function is to return used hydraulic oil builds up pressure and bursts. Possibly Heat? Getting a little annoying and costly mostly because of the cost of replacement oil. Any thoughts as to what is going on? If it helps any, the return line, which is a metal line exiting under the valve nest, is a forked line with another rubber line that attached under the valve nest

...so what I am saying is there are two low pressure hoses that attach to the right side steel return line. Hope I gave enough of an explanation. Any help would really be appreciated. Thank you and God Bless each and all. Doug Weigle...Doug in New jersey.

 

[Jim.ME]

What are the specs (PSI, etc.) on the hose you are getting? Any movement can be harder on a short hose as well. Is there any movement between the tubes at each end of the hose when you are digging stumps?

 

[jon f mn]

You probably need a one wire hose for there, likely hard to find. I have used 2 wire hoses in places like that because they are easier to find. But be prepared for a tough time installing a 2 wire hose.

 

[Harold Hubbard]

I would be looking for a restriction downstream from that hose.

I agree with using a wire reinforced hose if that is not the case.

 

[wore out]

You probably need a one wire hose for there, likely hard to find. I have used 2 wire hoses in places like that because they are easier to find. But be prepared for a tough time installing a 2 wire hose.

Fabric reinforced hoses come in a wide variety of pressure ratings, I don't believe the O.P. has told us what the hose he has been using is rated at?

 

[olddog]

I have a Case 580 B backhoe. And I need some help. As part of the valve nest under the (backhoe) valve nest (in the rear) there is a hydraulic return line that comes off the valve nest on the left side, and attaches to the return line, which exits under the valve nest through the wall on the right side of the machine. There are two steel lines, 1: off the far left side of the valve nest and 2: the return line that exits the casing below the valve nest through the right wall of the machine (reference sitting facing forward) which are tied together with a 1" rubber hose...not a steel wire cased hose. There is not much pressure in this return line as it appears to be a drain line. With that said, I continuously am "bursting" this rubber tie line, (at least six times so far) which then dumps most of my hydraulic fluid. The routine is the same: I use the "Hoe" section of the machine to dig out stumps, etc...and after a few weeks of use, this hose ruptures. The manufacturer who I buy the replacement 1" hose off of (less than 6" long) tells me the failed hoses rupture from the inside out, because of internal pressure. Interesting that a low pressure whose function is to return used hydraulic oil builds up pressure and bursts. Possibly Heat? Getting a little annoying and costly mostly because of the cost of replacement oil. Any thoughts as to what is going on? If it helps any, the return line, which is a metal line exiting under the valve nest, is a forked line with another rubber line that attached under the valve nestView attachment 124226...so what I am saying is there are two low pressure hoses that attach to the right side steel return line. Hope I gave enough of an explanation. Any help would really be appreciated. Thank you and God Bless each and all. Doug Weigle...Doug in New jersey.

I have a theory gained while building (and using) a log splitter....... It's like a water hammer.
when retracting a cylinder, more volume of fluid is flowing to the tank (VS what's being pumped out) against the head of fluid in the tank.
A quick shutoff of the valve, stops the flowing fluid so suddenly, it creates a shock (water hammer effect).
A fast operator and/or something with an electrically operated valve could continuously shock a normally low pressure return line such
that it blows; especially when it's up against max rated temperature.
Any way you could replace the line with a steel one? Also check the breather on the hyd tank.