Can't say that I've worked on exactly that forklift. But having worked on lots of oddball equipment over the years, I would suggest that you find the master cylinder, remove the cap, and smell the fluid. You can generally identify brake fluid easily enough by the smell and feel. Verify this by checking for labels and the like on/around the cap.
If you're still unsure, then don't put ANYTHING in it until you BECOME sure. This might require a call to the local dealership or scrounging around for a manual. But I know from experience that if you put hydraulic fluid into a system that's designed for brake fluid... you'll ruin EVERY seal in the brake system. Brake fluid into a hydraulic fluid system will yield similar (though less spectacular) results.
