Do jet pumps wear out and is there a way to test it.Last fall I pulled the jet up and found the check valve was leaking making the pump cycle every 15 minutes.I put in a new packer to match the pump and all I get is about 1 gallon a minute, so can I be losing pump efficiency around the impellers do to the time the pump has run. its a 2" well 123' deep 80' to the jet with no tail pipe and the pump is a jacuzzi 2 stage the pump shut off is at 50# and it wont go over that.