Hi ! Hope someone can help. We just drained all water lines and tanks.
My husband has winterized one time before about 3 years ago, and did same procedure: drained all water and lines, then He added antifreeze into water tank, turned on pump. And pump sucked it into all lines.. and out faucets, etc. And it was fine all winter.

This time, he has done same thing. Only,. Pump is running, but sounds like it is sucking air, and won't suck up antifreeze into lines. What ought we to do, to get pump working? (maybe last time he left some water in tank and that is why it worked.. and this time, water is completely drained? And pump needs priming ? )

You are correct. Your pump's lost its prime. Open the top of the impeller housing and pour water into it until it overflows. Now try it. If you can't keep water in the impeller housing then you have a faulty foot/check valve. Good luck, Tom

Thank you very much, will try today. Hope things didn't freeze up. We did best we could yesterday afternoon. But we have r.v. mechanic on call this morning, in case we can't get it running.
Thanks again VERY much !