Leaking main shutoff valve on a well

now that I'm going to replace the shower valve (from the help here in this forum) I've had to turn on and off the main water valve from the main well. I just went down into my basement to turn it off again and saw lots of water and a constant drip when the main valve is open. It's coming right through the valve and all over my floor. My question is how do I get the water to shut off from the well (aka the pump) so I can replace the main shutoff?

Also, is there anything I should do before I shut it off because I've heard of people having to 'prime' their well to get it back on. Any help would be appreciated!

 

Maybe it's a gate valve which has a packing nut that can be tightened to stop the leak.

If you have a submersible pump priming isn't an issue. A jet pump may have to be primed if the foot valve isn't holding.

bob...