My Comanche came with a wet vacuum pump and air oil separator. Neither component has so far proven to be very reliable. In the last 500 hours I've bought 3 vacuum pumps, two of which failed after 200 and 100 hours, respectively. And these are the wet pumps, which are /supposed/ to last longer.
I've had my mechanic fix oil leaking from the air/oil separator 3 times and it is again in need of attention. When everything is working right, oil consumption is 6 hours/quart, when things are wrong it is about 3.5 hours/quart. The difference seems to end up on the belly and the nose gear.
What are other people's opinions of this system? Should I continue to give it another chance? Is it time to give up and try dry vacuum pumps? Is one type of wet vacuum pump or air/oil separator particularly good or bad?