What's sort of funny is I ordered some cap nuts for 8mm bolts a few years back and ended up having to use a SAE wrench on it, none of my metrics would fit properly, either smear it and wouldn't go on
I ran my lines overhead and mounted the pump on the wall, be careful if you do decide to attach it to the post that you have enough clearance between the lift post inside and the bolt heads, not sure what kind of clearance there is off hand
I've had similar issues with mine but greasing mine seemed to help. I know you said you greased yours, but you should check the channels for buildup. I noticed when I was greasing mine there was a lot of buildup from the powder-coating, and I mean a lot.
Thank you so much for these pictures! Got mine installed up to the lock mechanism and was kicking myself since it's Saturday and they're only a Mon-Fri shop :beer: