your welcome
yes generally the filler cap might have a dip stick made on it or possibly on the older models the dip stick was separate usually located beside the filler cap, and also the filler cap is usually vented.
the position designations i suggested were based as if you were sitting on the seat.
Thank you! So if I'm looking at it and the battery is on the left, I'm assuming the cap closest to me on the right is the hydraulic?
Yes LPG
generally the hydraulic fill is over on the right hand side of the lift under the hood, there should be a fill tube with a breather cap and maybe even a dip stick to check the oil level. On the left hand side there should be a fuel cap either on the side of the lift inside a recessed part of the frame or under the hood, the cap should say fuel. Of course if the truck is an LPG truck that fuel tank will not be operational, most machines have the tank already installed from the factory as a standard part of frame assembly.
Most cats were like that.