Have an older hot tub. Put new control panel and pumps in about 8 years ago. Moved to new house. Used it only a few times after move being so busy. Sat a lot. Filled after being winterized. Ran fine on circulation and low speed. Turned on high speed and pump seal blew out of the 2 speed pump. Installed new pump. Loosened joints after fill to bleed. Turned it on, same thing. As soon as I turned on high speed blew the seal. Got a new seal and installed it in the newer pump. Made sure all the air was out of the lines. No big air leaks that I can see. Tub has no in line shut off valves. I’m at a loss. Don’t want to buy another pump for the same thing to happen. Thanks for any ideas or advice.