I use a vac. pump on between services (every 10K) but note that the indie (every 20K) drains the oil while it's on the hoist. That's OK with me and feel that with it being changed every 10k will help stop the formation of sludge.
I also get just under a 6 litres out by evacuation.
Wouldn't know how the stealer does it as I don't use them after a bad experience years ago.
AlanH.

