Sight glass

[RobJ]

If you checked it once and don't see any leaks, you should be good for some time. If you break something major like a hose, you'll probably notice or pump it all out while working.

Typical garage floors should have a little drop toward the door. Shops probably not.

Air should work itself out pretty quick after cycling everything being an open system.

I'd almost rather have a dip stick.

 

[Kenneth in Texas]

Mine always seemed to remain constant regardless of the leveliness, think i will change the oil and filter this weekend anyway since im about 20 hours overdue.