Air in 210 Loader cylinders

[gary_minnesota]

I started having this same problem last fall. I can eliminate the air by cycling the cylinders as mentioned, but when you're moving and spreading 10 tandem loads of fill, it get to be a real pain when your bucket gets floppy.

What was your final solution to this?

 

[davkir]

I have had a similar problem with my loader. I was looking at the manual and the regen (regeneration ) function looks like it could contribute to this. I may try disabling this function and bleeding the air out again and see how long it lasts.

Regen (Regeneration)
Function:

In "regen" position, the secondary spool will route the
return flow from the bucket cylinder into the pressure flow to
the bucket cylinders, causing the bucket to tilt forward
faster. The dual SCV handle will return to the center
position when released. If a cylinder is attached, the
cylinder will extend. If a hydraulic motor is attached, the
motor will stop rotating causing damage to the motor seals.
System Operation:
When the dual SCV handle is moved fully to the right, the
secondary spool will shift to connect both the number 1 and
2 ports to the pressure inlet port. This will pressurize both
ports. When a cylinder is connected to these ports, the
cylinder will extend. This is because the rod side of the
cylinder piston reduces the surface area of the piston and
therefore the hydraulic fluid does no have as much area to
push against. This pressure differential allows the cylinder
to extend. The fluid coming out of the rod end of the
cylinder is routed back to the secondary spool and is
combined with the pressurized fluid coming into the
secondary spool. This increase in fluid going to the base
side of the cylinder increases the speed at which the
cylinder will extend.
When the SCV handle is released, the spool will return to
center.
If a double rod cylinder or a hydraulic motor is attached to
the number 1 and 2 ports, placing the SCV handle in the
regen position will cause the system to dead head fluid into
the component. This will cause the component to be placed
at full system pressure and could cause damage to the
component. If these types of components are attached to
these ports, the regen functions should be locked out of
operation. See “Locking Out Dual SCV Regen Function” on
page 308.

 

[davkir]

I have had a similar problem with my loader. I was looking at the manual and the regen (regeneration ) function looks like it could contribute to this. I may try disabling this function and bleeding the air out again and see how long it lasts.

Regen (Regeneration)
Function:

In "regen" position, the secondary spool will route the
return flow from the bucket cylinder into the pressure flow to
the bucket cylinders, causing the bucket to tilt forward
faster. The dual SCV handle will return to the center
position when released. If a cylinder is attached, the
cylinder will extend. If a hydraulic motor is attached, the
motor will stop rotating causing damage to the motor seals.
System Operation:
When the dual SCV handle is moved fully to the right, the
secondary spool will shift to connect both the number 1 and
2 ports to the pressure inlet port. This will pressurize both
ports. When a cylinder is connected to these ports, the
cylinder will extend. This is because the rod side of the
cylinder piston reduces the surface area of the piston and
therefore the hydraulic fluid does no have as much area to
push against. This pressure differential allows the cylinder
to extend. The fluid coming out of the rod end of the
cylinder is routed back to the secondary spool and is
combined with the pressurized fluid coming into the
secondary spool. This increase in fluid going to the base
side of the cylinder increases the speed at which the
cylinder will extend.
When the SCV handle is released, the spool will return to
center.
If a double rod cylinder or a hydraulic motor is attached to
the number 1 and 2 ports, placing the SCV handle in the
regen position will cause the system to dead head fluid into
the component. This will cause the component to be placed
at full system pressure and could cause damage to the
component. If these types of components are attached to
these ports, the regen functions should be locked out of
operation. See “Locking Out Dual SCV Regen Function” on
page 308.

 

[SPYDERLK]

It seems to me that the regen function would help get rid of the air by flushing it all to the piston side of the cylinders during dump. It would then go back to the reservoir during curl. The question for me is how does a large amount of air accumulate in the first place in only some loader/tractor systems, and not in other, sometimes identical systems. My Kubota L2550/Loader behaves perfectly always. My Mahindra 7520/Loader has some noticeable air effects as some others on this JD thread-whereas some with identical JD tractors do not. In identical cases it seems that we may be looking at oil pickup problems since this is the only part of the system operating at negative pressure. Could there be leaks in the suction line to the pump or at the hydraulic oil filter? Alternately, is there some nuance in the return flow that jets fluid back into the reservoir causing air entrainment at the pickup? On identical systems this would qualify as a manufacturing defect. /forums/images/graemlins/tongue.gif
Larry

 

[SPYDERLK]

It seems to me that the regen function would help get rid of the air by flushing it all to the piston side of the cylinders during dump. It would then go back to the reservoir during curl. The question for me is how does a large amount of air accumulate in the first place in only some loader/tractor systems, and not in other, sometimes identical systems. My Kubota L2550/Loader behaves perfectly always. My Mahindra 7520/Loader has some noticeable air effects as some others on this JD thread-whereas some with identical JD tractors do not. In identical cases it seems that we may be looking at oil pickup problems since this is the only part of the system operating at negative pressure. Could there be leaks in the suction line to the pump or at the hydraulic oil filter? Alternately, is there some nuance in the return flow that jets fluid back into the reservoir causing air entrainment at the pickup? On identical systems this would qualify as a manufacturing defect. /forums/images/graemlins/tongue.gif
Larry