My Cherokee's water pump has been leaking for a while now. The leak was not as bad as I have seen in other vehicles, but I was losing about a quart of coolant every 2-300 miles.

Now, it appears to have stopped leaking. I last added coolant about 500 miles ago and the levels in the radiator and the reservoir have not went down.

How the heck does this happen?

Crud floating around in the coolant sometimes plugs the leaks. When it lets loose again it'll be spectacular. (replace the pump before that happens)

That is what I was thinking as well.

I drained and refilled the cooling system a couple of years ago, but sometimes find traces of what looks like coffee grounds or Copenhagen in the radiator filler neck.

I suspect that a previous owner may have dumped some kind of stop leak product in the radiator and that fix finally failed, but residual stuff plugged the leak back up.

Sound like a possibility?

sounds probable. I'd replace the pump and flush the cooling system til the cows come home.

when do the cows come home, exactly?

Every night to sleep and in morning for milking...When water pumps leak that the sign to get ready to replace me .When they stop its telling you when I leak next time your gonna be really stuck some place or on the highway and overheat severely .Change It ASAP...

I don't get it why not just replace the water pump including hoses, and coolant + radiator in one fell swoop, and be done with it?

Best bet...wonder if it has the oil driven cooling fan ?

I do intend to replace the pump. I just thought it was odd that it suddenly stopped leaking.

Jeep is a 2001.

Xj don't have them...