Bucket Cylinder extension?

[moojamboo]

I have installed my two bucket cylinders after being repacked. I have tried extending and retracting the cylinders without the bucket. The cylinders extend at different rates. The one which is first in the series will extend faster than the other. Once the first cylinder is fully extended the second cylinder extends faster. same occurs when retracted. There is about a 2 second time differential between the first cylinder being fully retracted/extended and the second cylinder. The hydraulic level seems good.

Is the difference in rates normal or should I be concerned? Any advice welcome.

 

[Transit]

Go and connect the cylinders to the bucket as normal, cycle it few times, add oil if needed and than go have a beer.

 

[SLHawkins]

The cylinders are working like they are supposed to. Like any fluid, hydraulic oil flows the path of least resistance too. Hook something rigid to them (i.e the bucket) and they will stay the same. The time lapse between movement in the cylinders is just your rate of flow.

 

[RickB]

Additionally the cylinders are plumbed in parallel, not in series. Were they in series, they would react together and would have to be of differing bore diameters.

 

[moojamboo]

My tractor has the hydraulics plumed in series. there is one tube that provides fluid to the cylinders and one that takes it away. The first cylinder gets fluid and excess continues to the second. both cylinders discharge into the same tube.

Does that mean that the cylinders might have different bore diameters and I need to switch the position of the cylinders so that they run at the same rate?

I hooked up the bucket and everything seems to work but i want to make sure i am not going to put extra wear on the cylinders.

 

[RickB]

My tractor has the hydraulics plumed in series. there is one tube that provides fluid to the cylinders and one that takes it away. The first cylinder gets fluid and excess continues to the second. both cylinders discharge into the same tube.

Your understanding of the terms series and parallel as they relate to hydraulics is incorrect. Your cylinders are plumbed in parallel.

If they were in series, the rod end of one cylinder would be connected to the base end of the other, and the valve would be connected to one end of each cylinder. There would be no 'tee"s' in the plumbing. A series connection of this type is also called a master/slave setup.

Your cylinders are fine as is.

 

[J_J]

If you follow the hose from the FEL valve work port A, you will find that the hose goes to a tee, and each one of those hoses off the tee, go to the base end of the cyl. The hose connected to work port B, goes to a tee and then to the rod end of the cyl. The cyls both work together, if connected to the same resistance, the bucket. If you try and test them not connected, the cyl with the least resistance will move first as RickB said.

 

[boggen]

not the best diagram in the world. but hopefully get series / parrallel figured out better.

like other said hook up the bucket like it normally should. operate the bucket say couple dozen times. fully curling and uncurling ((or rather fully extending and un extending the cylinders)) to help work out any air in the cylinders and lines. and everything should be ready to go.

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as far as different rates. longer pipes, longer hoses, more fittings goto one cylinder vs the other. this difference in length of pipes/hoses/amount of fittings can be enough to cause what you are seeing. it is part of fluid dynamics. also each cylinder when things were re tighten perhaps just slightly different perhaps tighter seal in one than another who knows. that is causing a little more resistance / friction than the other cylinder. and reason for difference in speed.

when the bucket is hooked up like normal. the cylinders will work just fine and each take 50/50 load / pressure placed on bucket. and respond just that way. technically i doubt any cylinder is actually 50/50 but pretty close to it.

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about only thing else would be, is when you unhooked and then rehooked up the hyd lines to cylinders. something go into one of the hyd lines. and partially plugging one of the lines up on cylinder that is moving slower.

but if cylinders are fully extending and fully contracting. even if one of cylinders were not moving as fast as the other due to say a partially plugged hose. it would only slow how fast the bucket curled / uncurled. and you would still have full pressure of bucket when in use to say lift something up.

also once the first cylinder fully extends if the second cylinder picks up to same speed the first cylinder was fully extending. i doubt it is a plug, but just the extra length of pipe / hose / extra fittings to get hyd lines over to the other cylinder. and/or the other cylinder has more resistance something is tighter for example a seal, or what not.