2 post car lift - lifting problems

[karp2005]

Hi everyone, finally installed used bend pack xl9-cx. Problem that I facing is uneven lift when empty: cylinder next to pump moves smoothly, another side lifts with delay(I have to stop and wait little bit while it catch up). I was told I have clogged line and replaced it. Now far side jerking like there is an air. My cylinders does not have bleeders.

What I tried to do: lift it slightly around 1ft and put down, then lift higher and higher several times. Looks that pumped air out of cylinder next to the pump, but not far side. Next I with loosing supply line fitting on far side did lift little bit up and down while air no longer go out. I was able to get it raising smoothly with that process when I stand on the arm next to the motor, but not empty. But next day everything repeated: it no longer smooth with me standing on the arm either.
What could be the problem? I do not see any visible leaks from the lines, oil is not leak from the cylinders when go on maximum raise, arm also lowered overnight just around 1in with locks off.
What can be the possible issue? I running out of ideas: if pump was the problem, then both cylinders will have the issue? Also if one of them has internal leak, when I raise on top position, air ****** on top of cylinder have to leak oil? But it doesn't.

Thanks for any suggestions.

 

[Kaizen]

I can't see how a lift would not have a bleed screw or allen screw someplace on the cylinder. Is this a new lift? You review the manual?
maybe the cylinder is installed backward so the bleed is where you can't see it

 

[WildBill]

Every lift I've messed with had bleed screws on top of the cylinders somewhere so you could slowly raise it letting the air out until it spits hydraulic juice on you.

 

[gizardlizard]

Give this a try: run the lift to its maximum height and while dead heading the pump, hold the down handle for at least ten seconds. Might have to do this a few times.

 

[karp2005]

Give this a try: run the lift to its maximum height and while dead heading the pump, hold the down handle for at least ten seconds. Might have to do this a few times.

Thank you and everyone, I think I was able to pump it up: issue I found - inside the oil tank supply hose was not good, so it sucked the air. I replaced it and now looks no air anymore in the lines. But now I see another issue: cylinder next to the pump pumping faster than away one without the load on the lift. Is that expected?

 

[RWorth]

doesn't your lift have equalizer cables to keep them level?

 

[karp2005]

They are. Cables level the arms. But when empty one side is pulling other side while opposite cylinder picking up.
I tried today with trailer around 1000lbs load on it and it lift pretty much fine. One side is 2in faster, but overall no issues. I think I need to tension cables little bit more to fix that

 

[RWorth]

yes, hydraulics will take the path of least pressure, so if one side is heavier than the other, the only way to keep it level is with the cable adjustment.
I have my 2 post set up totally independent of each other because my right post is on an I-beam trolly so I can push it to the wall and get it totally out of the way when not in use. I put adjustable proportioning valves on each post to keep it going level.

 

[karp2005]

Thank you. That is my plan too - I thinking to add flow divider to make it more even, not relying on cables.

 

[adsinnott1]

My 2 post does the same. Arms are connected via cables but the cylinders will raise independently without a load.

 

[finn]

Cable adjustment fixed this “issue” on my Bendpack two post lift.

It really wasn’t what I should consider an issue, but rather more part of the process of properly or completely setting up the lift.

 

[firebirdparts]

yes, hydraulics will take the path of least pressure, so if one side is heavier than the other, the only way to keep it level is with the cable adjustment.
I have my 2 post set up totally independent of each other because my right post is on an I-beam trolly so I can push it to the wall and get it totally out of the way when not in use. I put adjustable proportioning valves on each post to keep it going level.

That's amazing. Did you post anything about it in the lift modification thread? I would never have thought of that.

 

[Kaizen]

don't fret too much about both sides hitting the locks at the same time. It will eventually go out of wack again. I kind of like it hearing the two thud thuds so i know both sides are able to be lowered and locked.