The oozing (or weeping) can be due to several reason which will require you to do a little more checking.
1. We have been seeing an increase in weeping conditions on established tree since last year. I suspect that the drought and heat stress inflicted some damage to the tree, hence having some seepage from parts of the trunk. No treatment warranted - just maintain general health of tree.
2. Borer problems - look for holes (could be as small as a pencil tip size) close to the top of the seepage stains. If see holes, possible borer insect. May need to have an certified arborist to evaluate and suggest potential insect treatment.
3. Slime flux. Seepage is thick and has a off smell (fishy or overtly sweet). Occasionally will see bubbles. Definitely get an certified arborist out check the structural integrity of the tree, particularly if the falling of this tree can cause substantial damage. The smell may be due to fungi and/or bacteria and may indicate rotting within the tree.