I replaced the water pump on my tractor after months of waiting for parts and getting the wrong part and trying again. It's an old tractor that is hard to find parts for. Anyhow, finally, got the water pump replaced and tested, started it up, no leaks, things working well. Pumped up the flat tyres, and drove it around the yard all excited.

Then I lowered the 3-point hitch and when I went to raise it it wouldn't come back up, and the hydraulic pump was making a bad scraping sound. The hitch would vibrate and come up slowly but it sounded really bad so I decided not to try to raise it.

If it isn't one thing, it's another.

(Did I plumb the coolant into the hydraulics? No, no, that's not possible)