Following on from a thread on another forum where a member was asking about servicing an old trolley jack , I thought it would be worth copying the following over here for the benefit of newer members who perhaps have less experience of working on cars and have not heard some of the safety rules which may be obvious to others . My contribution to the thread was the following : "For safety , NEVER get under a car supported only by a jack . Use the jack ONLY to raise the car ; ALWAYS support the car with something else - like axle stands or ramps placed in such a way that there is no possibility of the car falling . By all means use the jack as a back-up support but never as the sole or primary means of support if you or anyone else is going to be underneath . People are killed every year due to not following this rule ; I lost one of my best mates ( who ought to have known better ) when a Ford Anglia he was working on fell on him - so I make no apology for going on about this . The jack that comes with your car is for changing wheels at the roadside only and is not meant to support the car for more than a few minutes . While a proper trolley jack is safer , I would still never get under a car supported only by one of these either - the very most I might do with only a trolley jack , apart from changing wheels , might be changing brake pads - but only if there is no risk of the car coming down on my hands and trapping them - otherwise I will ALWAYS put in at least one axle stand ." Not long after I posted that , another member came along with the following : " +1 I have lost 3 friends to date and one is severely disabled due to jacks failing, im only 25 so its obviously still a poorly communicated message. I'd never be entirely happy with a rebuilt jack. "