Maple tree disease? Prevention?
We viewed your photos. The tree looks very mature and thin. It looks like there is some trunk damage (we cannot say from what (could be old physical damage from lawn mower or string trimmer, etc.),
there is slime flux (liquid ooze around the trunk area), https://extension.umd.edu/hgic/topics/slime-flux-and-wetwood
and some possible borer holes. There is nothing you can do for these issues.
Keep your tree as healthy as possible by watering during dry periods and make sure mulch is not piled up around the trunk.
You did not mention where the tree is located and if it is near a structure. We recommend that you have an onsite diagnosis by a certified arborist. They can evaluate the tree and its structural integrity, and recommend the best way to proceed. http://www.treesaregood.org/