We just recently replaced our jet pump and nothing has been going well. It does great at first, builds up to the right pressure and then shuts off. But when you use enough water to make the pump kick on it sucks only air and most of the time cannot build up enough pressure. We replaced the check valve and most of the tubbing. We are pretty sure there is no intake leaks from were the pipe comes in from outside to the pump. The pump we took out would run non-stop, and be very hot. We wanted to just rebuild it, but was affraid once we took it apart it would crumble. There is enough water in the holding tank outside. Please if you have any ideas or have had this happen before we need HELP!