I have a 1993 Hitachi EX-120. I did some hose work and noticed I couldn't see any hydraulic fluid in the glass afterward. I thought I lost close to 5 or 10 gallons and it was already low before I started the work. After I put 10 gallons in I checked and I it was full beyond the top of the glass. Is there a big danger running the machine with the fluid being that high?
Did you properly configure the machine to check the oil (bucket full curl, dipper fully extended and boom down as far as it will go)?
Everything was about half way extended before I filled it.
It would have to be seriously overfilled for it to be a problem. 5 gallons over shouldn't be a problem.
I put 10 gallons in. I read that worst case it comes out of the cap?
If you're worried pump some out or could you disconnect a small hose and let it drain in a bucket? On mine I have a petcock on the bottom for draining.