I got the uhaul vacuum pump. My old pump diaphram didn't flow both ways like others have mentioned being a bad pump. After fighting to get the pulley off and losing, I picked up a vacuum gauge to make sure the pump was bad. It initially jumps to 20 on startup, but will only hang out around 7 or so. This was the case on the hose directly off the pump and on the hose at the booster. I'm pretty sure this means it's bad. So now I think I am resigned to buying a new pulley to the tune of $30.
I was really surprised when trying to pull the pulley. That thing bent so bad I though it would never work again. After putting the whole thing back on thouigh, I can't even notice a wobble to it.