Single Vs double action

[roger540]

I have an old superior loader that uses single action cylinders to lift. Weight of loader lowers itself.

I need to replace the cylinder but can only match with a double acting cylinder.

Can I use the double acting cylinder by plugging the top hole?

Adding a return hose would be difficult.

Also, Any thoughts on a seal kit or replacement cylinder ?

pin to pin retracted length = about 40 inches
stroke = 30 inches
Rod = 1.75 inch diameter
bore appears to be about same as rod diameter

thanks

[Chuck Oppermann]

A double acting cylinder will work but you can't plug the unused hole. You would have to put a vent on it to let the air out and keep dirt out.

[Craig Clayton]

That is it in a nutshell, on the vent look for a fitting that filters the air so you do not suck in micro dust.
Craig Clayton

[wdchyd]

I like to add what I call a "Pi$$ Tube" on the unused port on the D/A hyd cyl....

Basically adding a brass 90 deg fitting with hose barb and low pressure hose (rubber/poly or vinyl) and connect to a return line to tank....

It accomplishes a few things.........allows adding oil for lubrication on the other side of the piston head internally (helps big time for cyl longevity)....keeps dirt/grit/water contamination out.......and if the piston head does leak slightly it will bypass any extra oil out back to the reservoir when extending the cyls all the way out......

Your tractor will still function as a single acting hyd cyl and it won't change the operation......

[wdchyd]

Also, should you decide to change the control valve in the future you'll already be ready for the changeover to double acting (except for changing to high pressure hoses)........

[AKKAMAAN]

I have an old superior loader that uses single action cylinders to lift. Weight of loader lowers itself.

I need to replace the cylinder but can only match with a double acting cylinder.

Can I use the double acting cylinder by plugging the top hole?

Adding a return hose would be difficult.

Also, Any thoughts on a seal kit or replacement cylinder ?

pin to pin retracted length = about 40 inches
stroke = 30 inches
Rod = 1.75 inch diameter
bore appears to be about same as rod diameter

thanks

There are two ways to use the term Single Action cylinder, SA.


If you have one with no piston, just a rod (see my "true SA cylinder" on the picture), Then there must be external leakage to call the cylinder bad for dropping down the load. If no external leakage, cylinder good!!
Then you have to check the internal leakage in the control valve. There maight be a port related pressure relief valve that leaks. I doubt valve spool would leak (They last "forever" if oil is clean), unless it is not properly centered in neutral.

You can use a DA cylinder, just plumb the rod side straight to return line or to tank.....thats a very common way to do it on some mobile crane equipment

[AKKAMAAN]

I like to add what I call a "Pi$$ Tube" on the unused port on the D/A hyd cyl....

Basically adding a brass 90 deg fitting with hose barb and low pressure hose (rubber/poly or vinyl) and connect to a return line to tank....

It accomplishes a few things.........allows adding oil for lubrication on the other side of the piston head internally (helps big time for cyl longevity)....keeps dirt/grit/water contamination out.......and if the piston head does leak slightly it will bypass any extra oil out back to the reservoir when extending the cyls all the way out......

Your tractor will still function as a single acting hyd cyl and it won't change the operation......

+1