round bale door creep

[Windsweptfp]

have a JD375 roll baler. door creeps open when running, even when not under load. this baler has a hydraulic valve for tie & door. has a block separate that is a manifold / splitter for 6 hydraulic lines. I always run w/ valve set on tie & door still creeps open.
any input appreciated

 

[John in MD]

Your valve probably has an internal leak. If you have dual scv's switch remotes and see what happens.

 

[matthies]

If you don't have dual remotes, swap the hoses from side to side.

 

[Tx Jim]

With hyd oil at operating temp remove hose on butt end of cylinder, with engine operating at idle speed move hyd control lever as to close rear gate, count number of drops of oil in 15 seconds. Repeat test on opposite side of baler.

 

[Confusedfarmer31364]

TxJim. I need help with a 430 jd baler can you please send me an email.

 

[rustred]

have a JD375 roll baler. door creeps open when running, even when not under load. this baler has a hydraulic valve for tie & door. has a block separate that is a manifold / splitter for 6 hydraulic lines. I always run w/ valve set on tie & door still creeps open.
any input appreciated

You have one of the door cylinders leaking , by coincidence the same thing happened to me last night. Lucky I have a parts baler so I just swapped out the cylinder and all hood.

 

[Windsweptfp]

thanks for feedback. switched lines on remote. same result. gate creep. JD dealer said to try changing out hydraulic line connector to tractor remote. ???
will have to try TX Jims test.

 

[Tx Jim]

TxJim. I need help with a 430 jd baler can you please send me an email.

Confusedfarmer31364
I left you a YT PM because I don't know your email address.

 

[rustred]

thanks for feedback. switched lines on remote. same result. gate creep. JD dealer said to try changing out hydraulic line connector to tractor remote. ???
will have to try TX Jims test.

U need to verify the cyl’s are not leaking externally or internally. As that’s what will open the gate.

 

[DanielW]

To elaborate on RustRed's comment: Even if you have the valve held in the 'closed' position while running (you generally shouldn't do this as it will cause excessive heat/bypass - especially if it's an older tractor with a fixed displacement pump) the door will still creep open if one of the cylinders is bypassing. What you're essentially creating is a 'regen' cylinder condition: Pressurized fluid is being sent to the rod ('closed'/retract) side of the cylinder, but because the cylinders are leaking internally the pressure is equal on both sides of the piston. Because the cylinder has the rod on the retract/'close' side, there's less surface area on that side so it has less force than the barrel (extend) side. Thus: When a cylinder's bypassing internally, sending pressurized fluid to the rod (retract) side will actually cause the cylinder to extend. And because both cylinders are tied together, it will do this even if only one is bypassing.

While these aren't universally-true testing methods, some typical steps in baler gate/tension system diagnosis are:

i) Close gate, tension belts, disconnect lines from tractor, and see if problem persists. If problem is corrected, it's a problem with the tractor's control valve leaking internally.

ii) If equipped with hydraulic safety lock for the gate (most Deere balers are, but unfortunately I think the 375 has a mechanical lock?), tension up the belts, put the hydraulic safety lock in its 'locked' position and try forming a bale. If problem persists, it's likely a leaking cylinder, If problem is eliminated, it's probably the tension valve. This isn't a 100% perfect test, because many hydraulic gate safety locks only block flow to the barrel/extend side of the gate cylinders rather than both. But it usually lets you isolate a problem and figure out where to look.

iii) Do the gate-cylinder leak-down test as described by TxJim (always a good idea to check periodically every few years, even if there isn't an obvious problem).

 

[Texasmark]

I have a 375, 1991 edition, purchased used roughly 20 years ago. I had packing leaking on my gate cylinders and rebuilt them...parts easily obtained. Second problem was bales were sloppy. Got out the manual and read through some verbiage and that tractor has an overload valve on the left side of that manifold. Pressure is slight (able to see pressure when gate is closed on a 0-5k PSI liquid filled meter I installed on the supply line to the cylinders and found that a full bale....needle in the red on the side of the baler, was only running about 1800#. Replaced that valve, got the 3k I was supposed to have and bales started looking like they were supposed to. I weighed one of the Sorghum-sudan summer bales (pretty dry) and it was just shy of 800#.

 

[Windsweptfp]

To elaborate on RustRed's comment: Even if you have the valve held in the 'closed' position while running (you generally shouldn't do this as it will cause excessive heat/bypass - especially if it's an older tractor with a fixed displacement pump) the door will still creep open if one of the cylinders is bypassing. What you're essentially creating is a 'regen' cylinder condition: Pressurized fluid is being sent to the rod ('closed'/retract) side of the cylinder, but because the cylinders are leaking internally the pressure is equal on both sides of the piston. Because the cylinder has the rod on the retract/'close' side, there's less surface area on that side so it has less force than the barrel (extend) side. Thus: When a cylinder's bypassing internally, sending pressurized fluid to the rod (retract) side will actually cause the cylinder to extend. And because both cylinders are tied together, it will do this even if only one is bypassing.

While these aren't universally-true testing methods, some typical steps in baler gate/tension system diagnosis are:

i) Close gate, tension belts, disconnect lines from tractor, and see if problem persists. If problem is corrected, it's a problem with the tractor's control valve leaking internally.

ii) If equipped with hydraulic safety lock for the gate (most Deere balers are, but unfortunately I think the 375 has a mechanical lock?), tension up the belts, put the hydraulic safety lock in its 'locked' position and try forming a bale. If problem persists, it's likely a leaking cylinder, If problem is eliminated, it's probably the tension valve. This isn't a 100% perfect test, because many hydraulic gate safety locks only block flow to the barrel/extend side of the gate cylinders rather than both. But it usually lets you isolate a problem and figure out where to look.

iii) Do the gate-cylinder leak-down test as described by TxJim (always a good idea to check periodically every few years, even if there isn't an obvious problem).

Big thank you. good information.