I've had several of these fail because of the brass rods some were only a couple of years old and installed on showers and in such a position that no water
could sit in them and only fresh water with soap had gone through them. They occasionally get clogged with hair and need to be disassembled. I find that the rods seldom survive more than two disassemblies. I think the rods are so soft it is very easy to over tighten and fatigue them. I think the rods are just crappy materials and considering the price
of the pump they could put a few pennies into higher quality rods.