Hi mate.
Please, open your old pump firstly and clean the membrane. I wont be surprised, if your pump did not work simply because of the dust inside.
As for the Propump - it is Chinese brand. We use and sale them, but not a lot. No any complaints yet, but it is not SHURflo, Flojet or Aquatec, indeed.
I am really hope that your pump will work. Good luck.
regards,
Vadim