Originally Posted by womps
I also use air pressure with out disconnecting any lines. The same pressure regulator I use to maximize water pressure at 60 lbs will also regulate your air pressure to 60 lbs. max. Therefore your compressor can be set at 120 lbs and you can blow everything out and the compressor has no trouble keeping up to demand.
Bob, ditto on the above post, I do the same procedure with great results. In answer to your question about the water pump, I don't unhook any lines, I just use the pump to pump it's self dry, and continue with all the faucets, starting with the kitchen 1st then working back to bathroom. The inner diaphram on the water pump is made of a really good quality rubber which will last a long time. As for your failure, you don't think the shop that winterized it last may have used too much air pressure to clear the lines ? Lastly I just pour a/freeze in the drains. Good luck, happy trails & travel safe,