Cylinder synchronization issues

[JoeBob394]

I have replaced hoses on a no till drill. The raise and lower cylinders are installed in series. The cylinders are rephasing type, one with a 3.25 inch bore, and one with a 3 inch bore. The cylinders are mounted vertically, and I did lose a little fluid out of the lower fittings when I removed them. The drill has stops on the cylinders to keep the rods extended when not connected to the tractor etc.
The first cylinder (the raise side of the circuit) operated fine and the stop was easily removed. The other cylinder did not move off the stop, or at all when the raise function was tried.
My first thought is that there is no oil in the bottom of the first cylinder to move between the cylinders. It is my understanding that a rephasing cylinder has a means for fluid to pass through the cylinder (an orifice) that is actuated by full extension or retraction of the cylinder. I could manually remove the other stop and let the drill down if need be.
Any ideas on how to get the circuit flowing would be appreciated.
I tried to attach the diagram from AGCO but didn't have any luck.
Thanks

 

[oldnslo]

Does the rod end of one cylinder connect to the blind end of the second cylinder?

Does the diagram show an orifice for rephasing? What does it connect to?

 

[JoeBob394]

Thanks for responding.
The rod end does connect to the blind end of the second cylinder.
The cylinders are Midway rephrasing, which I believe used an internal practice to pass the fluid by at the end of the stroke.

 

[oldnslo]

Not sure how the rephasing works on your drill. Can you take a picture of the diagram from Agco and post that.

You somehow have to get all the air out of that closed loop between the cylinders

 

[RickB]

Typically you rephrase cylinders by fully extending them and keeping the remote valve stroked for a short period of time to force oil through the valve in the master cylinder piston until the Slave cylinder is fully extended.

 

[JoeBob394]

oldnslo, I have attempted the attachment. We will see if it will post. The cylinders are extended with transport stops holding the drill up.
RickB, I have extended and held the raise function for several seconds, but do not see any movement on the right side side cylinder, or and torque or movement on the hose between the cylinders. There was no change.
My next thought is to raise the drill manually and remove the stop, then let the drill down and then see if it will raise.

 

[oldnslo]

Somehow you have to get hose 5 full of oil. Can you apply pressure to lower and keep it pressurized without damaging the drill. Circuit doesn’t say which way the rephasing function works

 

[RickB]

Somehow you have to get hose 5 full of oil. Can you apply pressure to lower and keep it pressurized without damaging the drill. Circuit doesn’t say which way the rephasing function works

I agree, to a point. Usually the rephasing is done at cylinder extension. There’s no practical reason it couldn’t happen at retraction IF the rephasing valve is in the slave cylinder piston. A Parts catalog may answer that, and an operator’s manual may give instruction on rephasing.

 

[oldnslo]

I tried looking at an on-line parts catalog and all it stated was that all of the cylinders have rephasing and appear to be Cross brand. I could not find any info stating if this rephase on extend, retract or both directions. Cross website just stated at end of stroke.

 

[JoeBob394]

They are Midway cylinders. I'm not sure what series. They are supposed to rephrase at the end of the stroke. I will manually raise the drill enough to get the stop out and lower the drill to see if they will rephrase when retracted.
I thought the same thing about getting some fluid in line 5, and if retracting doesn't rephrase the cylinders I will mock up a hose to do that.
Thanks for the replies, I will report back.