I am fixing to change the fluid in my 85 XJ700N front brakes. The CD states that DOT 3 is recomended. Will changing to DOT 4 or 5 be more adequate for today giving the age of the bike or should I stick to the DOT 3.

CAPY, both DOT3 & DOT4 are moly-based fluids, which means they will absorb water (condensation). The DOT5 is a silicone-based fluid and it won't absorb water. The end result is your fluid will get diluted very quickly. Since water boils at 212 degrees and DOT3 or 4 at 400+, you can imagine how little stopping power you will have just from using the brakes a few times. As such, the DOT5 should be avoided. The good thing about DOT3 & 4 is they are completely compatible with each other and can be mixed. So stick with the DOT3, but use 4 if the 3 isn't readily available. Cary.

DOT3 and 4 are glycol-based, hygroscopic, water absorbing products. 5 is silicon-based. As ckyle29 says, stick with DOT3. DOT4 can be used in DOT3 systems, but DOT3 can't be used in DOT4 systems. Never mix 3 and 4, or 3 and 4 and 5!