Hydraulic Jacks – Practical Helpers for the Workshop

A hydraulic jack is a motorless tool that allows heavy loads to be lifted conveniently. It is manufactured in various designs.

Structure and Function of a Hydraulic Jack

A hydraulic jack consists of the following components

• Lever
• Pump
• Tank
• Hydraulic Cylinder
• Check Valve

The lever operates the pump, which pushes the hydraulic oil from the tank into the cylinder. The cylinder extends and lifts the load. After the lifting process is complete, the check valve is opened. The resting load then retracts the cylinder. Alternatively, the cylinder can also be pushed back manually, using muscle power.

The Different Types of Hydraulic Jacks

Hydraulic jacks are available in numerous designs. The most common devices of this type are the following:

• Pallet trucks – use an integrated hydraulic jack to lift loads, enabling pallets to be moved.
• Engine hoists – are hydraulic jacks converted into gantry cranes. They allow engines to be attached and safely lifted from the engine compartment.
• Transmission jacks – are used to safely lower or lift loads from a greater height. They are specifically designed to assist with vehicles on lifting platforms.
• Universal bottle jacks – do not have a specific application but are suitable for many tasks. They are not only designed for vertical movements but can also be clamped horizontally.
• Universal hydraulic jacks – have only a small contact surface. They are used to apply a large force to a small area.
• Motorcycle scissor lifts – are a practical aid for working on two-wheelers while standing.
• Hydraulic car jacks – have a greater lifting capacity than mechanical tools of this type. They are particularly well-suited for workshop use.
• Lift tables – are practical work aids for manual workstations. They help to raise workpieces to a comfortable height.

Working with a Hydraulic Jack

A hydraulic jack is an extremely practical tool. It is generally very wear-resistant. However, hoses, lines, sleeves, and valves can become leaky over time. The internal sealing rings in the cylinder also degrade over time. External leaks are easy to detect. They should be rectified immediately, as the device is no longer safe if it is leaking.

Internal leaks are indicated by the load gradually sinking again. In this case, too, the hydraulic jack should be disassembled and repaired. Spare parts are readily available for branded devices.

When lowering the lifted load, the check valve should only be opened carefully. Even a slight turn of the screw will cause the piston to retract. Caution: if the valve is opened too quickly, there is a high risk of injury due to the sudden descent of the load.