X-Block Hydraulic Adapter Kit – Add a Double-Acting Jack to a Single-Acting Power Unit

Add a double-acting hydraulic jack to your single-acting power unit

The Primary Mover X-Block Hydraulic Adapter Kit lets a compatible single-acting, power-up/gravity-down hydraulic power unit operate both your existing dump circuit and an additional double-acting hydraulic jack. Keep your existing power unit and select the function you want to use.

The manual selector valve chooses the dump circuit or jack circuit. The X-Block directional valve then routes hydraulic flow to extend or retract the jack, with displaced oil returning to the reservoir. Use your power unit’s UP button to power the jack in either direction.

• One power unit, two selectable functions: operate your dump body or hydraulic jack, one at a time.
• Powered jack extension and retraction: the X-Block changes flow direction.
• Complete jack hookup kit: includes the adapter, selector valve, hydraulic hoses and fittings listed below.
• Current selector valve: three ports with SAE-8 O-ring boss connections.
• Poly and Steel options: the only difference is the supplied tank-return fitting.
• Patent-pending X-Block design.

Buying a jack for an existing single-acting setup?

Choose your Primary Mover single hydraulic jack, then add this X-Block kit. Select the bolt-on or weld-on jack you need from our jack-only listing, and add the Poly Tank or Steel Tank X-Block kit to match your existing power unit’s reservoir and return connection.

Together, the jack and matching X-Block kit provide the hydraulic components needed to connect and operate that jack from a compatible existing single-acting power unit. The kit includes two 72-inch jack hoses. Confirm hose reach and connection compatibility for your installation.

The hydraulic jack and power unit are sold separately. This listing supplies the X-Block adapter kit; it does not include a jack, power unit or reservoir.

What both X-Block kits include

• 1 × X-Block hydraulic adapter with red directional-control valve
• 1 × three-port manual selector ball valve with SAE-8 ORB ports
• 1 × short hose from the power unit to the selector valve
• 1 × hose from the selector valve to the X-Block
• 1 × return hose from the X-Block to the reservoir return connection
• 2 × 72-inch hoses from the X-Block to the hydraulic jack
• 2 × straight JIC fittings for the hydraulic jack
• 1 × tank-return fitting matched to your selected kit

Choose Poly Tank or Steel Tank

Both versions use the same X-Block, selector valve, hoses and jack fittings. Only the tank-return fitting changes.

These fittings match common Primary Mover reservoir configurations. Verify the actual return-port size before ordering: tank material alone does not guarantee the connection size on every brand.

Does the return hose have to connect directly to the tank?

No. Some power units have a suitable return port on the power-unit assembly that routes oil back into the reservoir. Where compatible, that port can be used instead of connecting directly to the tank.

A direct tank connection is often the simplest installation. If you have a Primary Mover, KTI or another power unit and are unsure which return connection to use, send us photos of the unit, reservoir and available ports. We can help identify the appropriate connection and fitting.

How the two valves work

• Manual selector ball valve: directs your power unit’s output to the dump circuit or the X-Block jack circuit.
• Red X-Block directional valve: selects which side of the jack cylinder receives pressurized oil and which side returns oil to the reservoir.

Basic jack operation

1. With the pump stopped, select the jack circuit on the manual selector valve.
2. Set the red X-Block valve to the jack-extension position.
3. Press and hold UP on your existing power-unit control to extend the jack.
4. Release UP and stop the pump before changing the red valve’s position.
5. Select the jack-retraction position, then press UP again to retract the jack.
6. Stop the pump and return the selector valve to the dump circuit when finished.

Extension and retraction positions depend on the installed hose routing. Follow the installation instructions and identify both directions before operating under load. The DOWN button is not the jack’s powered-retraction control in this arrangement.

Use with a jack equipped with dual counterbalance valves

We strongly recommend pairing the X-Block with a double-acting hydraulic jack equipped with dual counterbalance valves, such as the applicable Primary Mover hydraulic jacks.

Properly configured counterbalance valves help hold the load when the pump is stopped and control load-driven movement during operation. This is especially important when changing hydraulic flow direction.

A jack without suitable load-control valves may move unexpectedly or retract rapidly if its hydraulic circuit allows loaded oil to escape. A check valve on only one side does not provide equivalent control in both directions.

The X-Block directs flow; it does not replace the jack’s load-holding valves. Other jack configurations require application-specific hydraulic review and are not our recommended pairing.

Compatibility and installation

• Power unit: compatible single-acting, power-up/gravity-down configuration.
• Jack: compatible double-acting hydraulic jack; dual counterbalance valves strongly recommended.
• Return connection: a suitable return path to the reservoir is required.
• Hose reach: two 72-inch jack hoses are included; check your mounting layout.
• X-Block pressure rating: up to 3,200 PSI. Operate within the lowest applicable component pressure limit.

X-Block questions and answers

Installation help and videos

Visit our product and technical video page for available walkthroughs.

Need help choosing your kit? Call 985-888-6554 or email sales@primarymover.com with photos of your existing power unit, tank return connection and jack.