Not what I did, but what my jack did. It peed on the shop floor yesterday.
So, just a PSA for everyone:
If you're jacking a vehicle up, even if you're only jacking it up for a short while, do not neglect the use of jack stands.
Yesterday I was doing some work on my wife's van. Have never had any issues with my jack - I've had it for nearly 20 years. Used it a number of times in the past couple weeks and had various corners of the van jacked up in succession yesterday. Jacked up front driver's side - needed to pull the wheel to check on the front end and see if there's anything else I need to replace up there besides struts. Of course I used a jack stand, something dad drilled into me. And good thing. When I let the van down, there was a small puddle of oil that had leaked out of the jack. Thankful it wasn't a quick/catastrophic failure that resulted in damage or injury, and thankful that I did have that jack stand in place while I was checking things out. Things could've possibly gone way different than they did.
So, there will soon be a new jack in my shop. This one's not to be trusted or used any longer.