What you need to know about air jacks

Back when they first became popular, I tried an air jack. It worked well, but I was surprised by a big sooty blob that mysteriously appeared on my shirt. Those of quicker wit would have figured it out immediately, but it took a while to for me to realise it was from the exhaust that had been inflating the bag and which had later blown out the nozzle onto me when being folded away.
The incident provided the first clue that using an airbag jack is not quite the fun depicted in advertising showing smiling and relaxed couples or families  lifting their loaded 4x4 tall on a gleaming bag full of fumes.
An air jack is better than the mechanical jack that comes with the vehicle for several reasons, one of which is that OEM jacks are sometimes terrible. The proper jacking points under the body are often inconveniently placed, except for use at the side of the road, and the jack will usually not provide enough elevation yo do the particular job.
Over the years I’ve used several brands of bag jack, in a variety of situations, but have gone back to a high-lift. Here are the reasons why:
• Despite taking care, it’s not hard to puncture the bag.
• They vary considerably in the ability of the hose to stay on the vehicle’s exhaust. The best ones stay on very well. Your jack’s hose may not fit on another stranded vehicle’s exhaust at all, or vice versa. However, there’s no reason why it has to be attached to the stuck vehicle.
• Properly setting the bag up under a vehicle is tricky. It’s at its best on sand and in paddocks. It’s not just a matter of placing the bag under the vehicle, avoiding the exhaust or other hot parts; it also needs some kind of mat at the base and between the bag and the chassis. All very fiddly, especially working on your own.
• Every air jack I’ve used slowly deflates, some faster than others, so don’t muck around if you’re changing a wheel; or keep giving it a top-up.
On the other hand, an air jack has some good points:
• It’s light and stows easily.
• Most vehicles don’t have anywhere to high-lift from.
• Apart from possible soot assaults on shirts, it’s not inherently dangerous.
• Choose wisely, treat with care and it will last for ages.
Using an air jack is easy, once set up. The correct way to use one is at the nose or tail rather than at the sides, presumably to avoid having the vehicle rolling when pumped high. However, I often broke this rule and have lived to tell the tale. And never, ever, get underneath a vehicle raised only by an air jack. Or any other jack, for that matter.

  PH