Been there...done that...smelled the smoke. Unless it's a really, really, really old car, the motor bushings in those pumps are plastic and will quickly melt if run continuously. They are designed for only very brief run-times...seconds.
Oh I used old 1989/90/91 Toyota Liteace ones which worked fine for me but I'm not sure if I ran them long enough to do any damage. Thanks for the heads up, I wasn't aware that they were plastic, I wont be trying to get motors out of them so