A car jack is needed whenever you need to raise your car to carry out an emergency repair – such as to change a wheel when you get a puncture – or if you need to spend more time under it, to renew the engine oil or replace the exhaust system, for example.
What car jack do I need?
There are three main types of car jack: the trolley jack, bottle jack and scissor jack. They all do fundamentally the same thing, but in a slightly different way, and some types are more stable than others (as we explain below).
How does a car jack work?
In all three cases, make sure your car is on an even, level surface; it should also be on solid ground such as Tarmac or concrete, and not gravel or turf, which will cause stability issues.
Now locate the car's jacking points – your Haynes Manual shows you where these are within Roadside Repairs. Your owner manual will also tell you where it is safe to lift the car from.
Watch: three types of car jacks and how to use them
What is a scissor jack and how do I use it?
A scissor jack is the one you'll usually find in your boot, together with a spare wheel. It's the cheapest and smallest option available and comes with a handle to wind the arms apart, which then lifts the car up.
Position it under the jacking point and wind it clockwise until the car is lifted off the ground. To lower it back down, it is simply a case of winding the handle the other way.
How does a trolley jack differ?
A trolley jack is a safer, more stable and quicker option and is the choice of professional mechanics. Its wheels mean you can roll it into position easily, but before you do, start by making sure the relief valve is closed – refer to your jack's instructions but this is usually done by using the end of the removable handle.
Then it is simply a case of inserting the handle and pumping it until the cradle reaches the jacking point. To lower it back down, take the handle out and twist the relief valve anti-clockwise to open it, taking care to do so steadily to lower the car slowly.
What about a bottle jack?
The bottle jack works in much the same way as a trolley jack, using hydraulic force to lift the car. It has the bonus of being smaller and easier to store than a trolley (so you may be able to carry it in your car boot) but this means it isn’t quite as stable.
Again, make sure the relief valve is closed, then unscrew the top of the jack to the correct length – the instructions should tell you how far you need to extend it. Then position it under the jacking point, insert the handle and pump until the car is raised.
Lower it again in the same way as the trolley jack.
Do I need axle stands?
If you plan on raising the car because you need to get under it, then yes, you'll need axle stands to support the car safely. You must never get under the car with just the jack supporting it.
As with any type of car jack, axle stands must only be used on firm, level ground. Make sure the ones you buy can support the weigh of your vehicle.