The following is a list of the 31 parts that make up the hydraulic bottle jack. Most pieces are made of steel, that has been shopped in some way, usually on a mill or a lathe. The non steel parts are either rubber or plastic and are purchased or injection molded.

The name Jack is of English origin and means “God is gracious.” Derived from the name John, Jack became popular in the Middle Ages. Before landing on Jack, the name went from John to Johnkin to Jankin to Jackin.

two types

Stands are simple mechanical devices in the sense that typical failures (cracks, bends) are easily observable by a simple visual inspection. That’s what makes them inherently safe. A hydraulic jack on the other hand is sophisticated enough to have hidden failure modes (leaky seals / valves, etc.)

indefinitely

Jack failures are pretty much human errors. Overloaded, wrong fluid, misused, etc. etc. Jacks don’t fail as often as humans do.

Honestly, unless you have all the variables that you can change in your control, this should never happen. If you have a vehicle which is heavier than what the jack stands are rated for, the stand will fail, and the vehicle’s weight will give in.

You can keep the jack under there to be on the safe side, but make sure it’s not unbalancing the car in any way, or fighting against the stands. If while working under the car you remove the wheels, it’s never a bad idea to put them under the car as an extra safety measure.

If the car is jacked at the proper points, it’s fine. Put plywood under the stands if it’s on asphalt so the stands don’t dent it. Otherwise, totally fine.

The Only Safe Way to Work Under a Car – Jack Stands. Any time we think about doing any maintenance to our cars, chances are good it will need to be off the ground. To remove a wheel, the tire needs to be at least a couple inches off the ground.

Floor jacks can be used on a wide variety of vehicle body styles and sizes, and can fit in most garages and workspaces. Sure they’re not as portable as other styles of jacks, but they’re safe and capable. They are also pretty easy to use.

I would definitely not use the jack stands with the ramps. It’s not possible to chock your wheels on a ramp, so if you are supporting the front of the car with the ramps and the rear with the jack stands, it would be easy for them to roll a little bit forward or back and fall.