What safety precaution should always be taken when using a jack?

Using jack stands for support is essential because they provide a stable and secure means of holding a vehicle in place after it has been lifted. Jacks are designed for lifting, not for sustaining the weight of a vehicle, and can fail or slip, leading to severe accidents. Jack stands, on the other hand, are specifically engineered to support the vehicle's weight, ensuring safety for anyone who may be working underneath.

Choosing to position the jack on a sloped surface compromises stability and increases the risk of the vehicle rolling or shifting unexpectedly. Lifting a vehicle without first checking its weight can lead to using insufficient equipment, which may not safely handle the load. Engaging the engine while lifting can create unnecessary risks and complicate the lifting process due to shifting parts or potential movement if the vehicle is not properly secured. Thus, using jack stands is a fundamental best practice that significantly enhances safety when performing any work beneath a vehicle.