Hydraulic problem stacker

[fizzy]

I asked ages ago but no answers.
I have a nice pallet stacker. Hydraulic ram. Went to jack it up. No oil. Filled it up. Jacked no problem but won't come back down again. Any ideas? Sticky valve perhaps?

 

[m_c]

Most likely a sticky valve, or could just be tight seals for some reason.
Have you tried putting some weight on it?

 

[fizzy]

Not this time but when I asked before it wouldn't lower even with a hefty weight on it. Only reason it comes down is due to oil leaking.
It was triggered by transporting it lying down in a van. Never worked since

 

[brightspark]

not over filled with oil is it i did it once and mine wouldnt go down till i tipped some out

 

[m_c]

Overfilled, or the vent being blocked could also cause the problem.
Try taking the filler off, and see if lowers.

 

[zzr1200]

On forklifts there is a lock valve right at the bottom of the lift cylinder that closes to stop the flow of oil out of the cylinder, incase the flexible hose to the lift cylinder is damaged and blows out. Its possible (if it's fitted to this lifter) that laying it on it's side has dislodged a part or has allowed a bit of dirt/grit into the valve and locked it.

Can you find a data plate/model number, I'll have a look and see if I can find anything out.

Is the lifter now at full height???

PS. Also better photo's of the pump and lower valve area might help, clean the areas if possible.

 

[fizzy]

On forklifts there is a lock valve right at the bottom of the lift cylinder that closes to stop the flow of oil out of the cylinder, incase the flexible hose to the lift cylinder is damaged and blows out. Its possible (if it's fitted to this lifter) that laying it on it's side has dislodged a part or has allowed a bit of dirt/grit into the valve and locked it.

Can you find a data plate/model number, I'll have a look and see if I can find anything out.

Is the lifter now at full height???

PS. Also better photo's of the pump and lower valve area might help, clean the areas if possible.

Cheers. I suspect bottom valve problems as well. Will take more pictures in daylight.

 

[fizzy]

Overfilled, or the vent being blocked could also cause the problem.
Try taking the filler off, and see if lowers.

No it doesn't budge with filler cap off.

 

[fizzy]

On forklifts there is a lock valve right at the bottom of the lift cylinder that closes to stop the flow of oil out of the cylinder, incase the flexible hose to the lift cylinder is damaged and blows out. Its possible (if it's fitted to this lifter) that laying it on it's side has dislodged a part or has allowed a bit of dirt/grit into the valve and locked it.

Can you find a data plate/model number, I'll have a look and see if I can find anything out.

Is the lifter now at full height???

PS. Also better photo's of the pump and lower valve area might help, clean the areas if possible.

Full height.
See photos of bottom valve. What does the thing on the right do?

 

[zzr1200]

That could well be a flow lock valve, I would support/wedge the inner mast and/or carriage so it doesn't fall/collapse (make sure you get it right first time) and carefully remove that valve assembly., it will dump oil on the floor, unless you have an oil catch tray.

 

[fizzy]

That could well be a flow lock valve, I would support/wedge the inner mast and/or carriage so it doesn't fall/collapse (make sure you get it right first time) and carefully remove that valve assembly., it will dump oil on the floor, unless you have an oil catch tray.

Cheers.
I don't really need it as I have a forklift but I can get my forklift down that end of the warehouse. I used to use it as an adjustable height welding bench

 

[fizzy]

That could well be a flow lock valve, I would support/wedge the inner mast and/or carriage so it doesn't fall/collapse (make sure you get it right first time) and carefully remove that valve assembly., it will dump oil on the floor, unless you have an oil catch tray.

Thanks everyone for the suggestions. It now WORKS.. Big mess on the floor though.
I unscrewed the cap bottom right. There is a bolt/screw which retains a spring. Has never been touched. I removed it and fluid gushed out. Spring has a small pointed cone on the end. I found it only comes back down now if the screw is almost all the way out. Its working fine now but why did it work before with it all the way in?
Happy but baffled!

 

[RichardM]

Crap in the hydraulic fluid blocking the hole maybe?

 

[fizzy]

Crap in the hydraulic fluid blocking the hole maybe?

Quite possibly.
It does NOT work. That valve on the right is the relief valve. I will have to strip the whole ram down. Obviously a fault in the return valve somewhere

 

[jjwoods]

Thanks everyone for the suggestions. It now WORKS.. Big mess on the floor though.
I unscrewed the cap bottom right. There is a bolt/screw which retains a spring. Has never been touched. I removed it and fluid gushed out. Spring has a small pointed cone on the end. I found it only comes back down now if the screw is almost all the way out. Its working fine now but why did it work before with it all the way in?
Happy but baffled!

I believe the spring setup is to do with the oil flow to the ram, the valve can be set for a different speed etc, also the ram is huge i wouldnt attempt to move it by hand just hook it up to a system and test it, also some rams have valves that wont open without fluid pressure behind

 

[fizzy]

I believe the spring setup is to do with the oil flow to the ram, the valve can be set for a different speed etc, also the ram is huge i wouldnt attempt to move it by hand just hook it up to a system and test it, also some rams have valves that wont open without fluid pressure behind

The spring with a pointed cone is the relief over pressure I think. If you try to lift too much it opens. I assume anyway.

 

[zzr1200]

Its working fine now but why did it work before with it all the way in?
Happy but baffled!

....... Just one of those mysteries.

Does it lower faster now with a load on it???