580E boom bleeding down

[Bigredtruck8]

I just bought a 580 super E. I noticed the boom will not hold position when you let go of boom lever. Example sitting your self over a ditch. With front bucket on ground and out riggers up boom will bleed off and it sounds like fluid running through the front end loader valve body. What are the possible problems? Should I rebuild the boom cylinders? The boom cylinders seem to be dry.
Thank you,

 

[Mitchell14]

I would check the counterbalance/check valves because they should be holding the load of the boom. If not that then maybe a spool is sticking open in the control valve? Hope this helps

 

[melben]

(1) Check the bottom of the boom cylinder tubes where they could contact an outrigger pad which was in the up position , I have replaced many damaged barrels from people swinging the boom to the side and letting the boom cylinder contact the upright stabilizer pad.

(2)The Case valve was famous for o ring failure on the check valves located under the secondary but that usually caused interaction between the spools causing another function to move when a different lever was moved. Also the secondary valve o ring could have failed

 

[Tinkerer]

Welcome to HEF, Mitchell14 !

 

[Coy Lancaster]

Welcome to HEF, Michell14 like melben said check the boom cylinders for any damage first off. Then we can go from there,

 

[hookedondiesel]

Hydraulic fluid will always find the weakest link, if you suspect the loader vale body, have someone check it for leaks or use a mechanic stethoscope to listen for the bypass in the loader valve body while you lift the boom in the up position, the machine can be shut down for this test.

 

[Bigredtruck8]

Okay, thank you for information. Don’t see any damage to boom cylinders.

 

[Coy Lancaster]

Ok if there is no damage on either cylinder then stretch your boom all the way out then power down like you are trying to pick up machine with boom. Hold the lever in the down position for a couple of minutes then check each boom cylinder with your hand and see if one is hotter than the other. If one is much hotter than the other then that is the one that is bypassing. The reason you need to do this check is because you still could have damaged piston seals. If you don't find one leaking then you'll need to check the boom up circuit relief valve (which is on the bottom) for being stuck or out of adjustment.
Oh I forgot to ask if both cylinders looked straight and no bow in tube or rod.

 

[Bigredtruck8]

Looks to be leaking from bottom of valve on right side of loader control when boom has pressure. Boom cylinders hold the weight of boom until you lift machine. Is this power beyond o ring issue?

 

[Bigredtruck8]

Where is the best place to get a shop and parts manual?

 

[Tinkerer]

I have the service manual for the 580SE. Not much different from your E.
The SE has more horsepower and different type of brakes I thinks.
If you want, PM me your email address I can send you a link to my Google Drive and you can download it.
Go here for all the other manuals for your 580E.
https://www.minnpar.com/manuals5.as...S PARTS MANUALS&SSSFName=CASE 580E SE SUPER E

 

[old and slow]

You have a piston seal leaking internally in one or both of the cylinders. The way to check it is. Disconnect the cylinder from boom. Disconnect and cap the piston side of cylinder. Next apply pressure to the rod side of cylinder. If the seals are ok it will stall or go to bypass. If the seals are bad the rod will start moving out extending. The reason why is the surface area is greater on the piston side than the rod side, the fluid goes around the piston seal and pressurizes the piston side. Do the apply pressure slowly, sometimes the movement is very slow, but indicates a bad seal. Do one cylinder then the other. You have to have proper caps and plugs.

 

[melben]

Are you talking about boom leak down from a travel position or the boom leaking down when you are trying to lift the machine up with the boom down pressure? It was not clear to me if the boom leaked down to the ground in the normal parked position . The boom down pressure has a very low boom down relief setting, I do not know exactly but would not expect boom down secondary to be not much over 14-1500 PSI and the boom not holding the whole weight of the machine is normal with the boom stretched out and front bucket holding the machine front wheels off round, to satisfy customer complaints of not being able to set the machine over a ditch I have increased the pressure on the boom down secondary. If the boom is not leaking down in the normal parked position cylinders are most likely not the problem. In a properly working machine the boom down would hold the machine up till the lever is let off then the boom will drop over secondary relief.

 

[page305]

I have the service manual for the 580SE. Not much different from your E.
The SE has more horsepower and different type of brakes I thinks.
If you want, PM me your email address I can send you a link to my Google Drive and you can download it.
Go here for all the other manuals for your 580E.
https://www.minnpar.com/manuals5.aspx?FName=CASE (CNH) MANUALS&SFName=CNH (CASE) LOADER BACKHOE MANUALS&SSFName=BACKHOE (CASE) 580 SERIES PARTS MANUALS&SSSFName=CASE 580E SE SUPER E

I just bought a 580 Super E (my first backhoe and it's rough) is that offer the the service manual link still available?