How Does The Atlas IV Hydraulic Trailer Jack ST23FR Retract Completely?

Question

Question:

How does the jack retract completely if it is single acting once there is no longer weight compressing the cylinder?

asked by: Jerry

0

Expert Reply:

Hey Jerry, thanks for reaching out. The Atlas IV Hydraulic Trailer Jack # ST23FR is a single-acting hydraulic jack, so hydraulic pressure is only used to extend the cylinder. Once the trailer is coupled and the tongue weight is off the jack, the hydraulic pressure is released and compressed air is applied to the opposite side of the piston to fully retract the jack. It doesn't rely on springs or the trailer's weight to pull the cylinder back in.

So even after the foot lifts off the ground and there's no longer any load compressing the cylinder, the air pressure continues retracting the jack until it's fully stowed.

What kind of trailer were you thinking of using it on?

expert reply by: Jesse M

0

Atlas IV Hydraulic Trailer Jack # ST23FR
(click to enlarge)

Jerry

6/30/2026

PJ gooseneck equipment trailer. It looks like, looking at the installation instructions from Stillwell that a NeXgen single acting adapter is added to the retract port to add air pressure to that side of the jack cylinder. Does that sound right, and do you sell that adapter?

Jesse M.

7/1/2026

@Jerry Yes that's right, but we don't sell that adapter here. Might need to source that directly from Stillwell.

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How Does The Atlas IV Hydraulic Trailer Jack ST23FR Retract Completely?

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