if you can't see the oil in the g;lass and the bead is on the bottom then it would be useless to remove the glass unless you want to stick something in there and see just how low it is ------------The machine will still operate about 4.5 gallons low of oil , it might not acceive the max boom up , when it quits operating it is a five gallon can low , the sight glass system is bogus , the range in the glass is about 2 quarts , so you don't really know how low it is till you fill it , and it is hard to fill it and check the glass at the same time by your self , and it is very easy to over fill , it has been like that for a while , you would think they could dream up a better system , like keep the glass for quick reference but add a dip stick ---------------wolfman jack was good listening back when , full moon this week coming , have fun