There always has to be a reservoir near the top of the hydraulic system. Follow the hoses and line. Large diameter lines are return to the reservoir, while smaller ones are pressure to the pistons. There usually is not a dipstick, but you open the filler and simply look in.

There should be a tank that holds the hydraulic fluid. Open the cap and look in the tank. If there is a dip stick, it might be on the cap.

Probably on the cap of the oil tank - unscrew and check.

It depends totally on the make and model. Ours has a line on a translucent oil tank.

Maybe it has a sight glass.

We're suppose to be be checking the hydraulic oil on are forklift at work as part of are pre-operational inspection. No one has ever done this! And I was wondering where I might find to show my employer