Teach me about water pumps?
Okay, I'm totally new to RVs, and I've taken on a complete rebuild of a 69 overlander. I'm a number of steps away from getting serious about plumbing, but I had some questions.
First, I found, uninstalled, the original water pump. At least I assume it's original. Has a little toothed belt on it. Were these any good? Do I want to use it (assuming it works), or is it a museum piece that should be replaced now rather than having it conk out in the middle of a camping trip?
Next, just a general question: how does a water pump know when to work. I understnad how pumps work, my question is simply what tells the pump to begin pumping? Is the water system always under pressure? Or does opening a tap somehow tell the pump to start pumping?