This truck used dot 3 when new.
I kind of think Jon_G's answer was in relation to the differences between Raymond and Crown stand up trucks, as all US sold cars since about 1996 had a design requirement for a clear or opaque brake fluid reservoir, and I just don't see no magnet being able to stick to the reservoir on my ford, but I am real sure it also uses DOT 3.

To get a correct & safest answer call your lcoal CAT lift truck dealer & ask them.

JonG, I am not trying to be a smart ***, but what if the resirvoir is plastic?????

Oil Burner
Rule of thumb I was taught

If the reservoir is steel - if a magnet sticks to it the fluid is usually DOT3
If the magnet does not stick DOT 5

oilburner hello.
With the oil brake. If the pump the brakes, there is a green paint should be used only mineral oil the color green to avoid being attacked and bombit rubbers of the pump. only if you change the rubber to the DOT 4, otherwise even think to use other oils DOT. if it has no color signal oil being used is DOT 4 which is now universal for all vehicles except those with said signal. Generally most vehicles use this type of oil (mineral) are the Europeans, for these oils are not as aggressive and greener. No one more hug to all the guys.