BOTTLE JACKS
OFTEN seen as an upgrade to the screw jack, hydraulic bottle jacks are one of the most common jacks you’ll see. They’re available in multiple SWLS, from as little as 2000kg right through to 20,000kg; although, unless you’re planning on balancing five fully loaded 4x4s on the one jack, those weights may be overkill.
Much like a screw jack, hydraulic bottle jacks are incredibly compact, often occupying the spot the OEM screw jack came in. Rather than a series of gears inside, a bottle jack works by pumping hydraulic fluid from the storage container (the large bottle-shaped part) into the chamber underneath the jack’s ram. The benefit of this over a screw jack is the huge mechanical advantage you get, making it easier to move heavy loads.
The downside is that due to their design they aren’t able to lift as high as a screw jack. Despite having a larger capacity (10T) our bottle jack had a maximum lift height of 480mm, with only 140mm of available travel and a further 80mm in the screw-top adjuster. They’re also considerably heavier than a screw-type jack and are more difficult to lower due to requiring the pressure release valve to be cracked, rather than a second pump to pump it out. Careful attention should also be paid to not damaging the seals.
Bottle jacks provide a larger lifting force over a smaller distance, and they’re available in many sizes. Some can be optioned with angled V mounts to more securely grab an axle tube; although, that will remove their ability to be used as a press. They’ll serve as a suitable replacement to an OEM jack, but whether or not they’re an upgrade is up for debate.