Look up slime flux disease.

Not much you can do and doesn't hurt the tree.

i have never seen a JM that big ... can we confirm the ID .. would need a pic of leaves ... hard to see those few couple leaves ... if they are in fact.. attached to this tree ...

and can you show us a pic of the whole tree ... to look at its structure ...

i THINK ... as of right now ... you are seeing a reaction to poor tree structure ... and regardless of the leaking.. you might have a failure of one or the other of the main trunks involved .. and i cant really tell what the 3rd trunk is ...

does it threaten anything.. if it should fall???

ken

Straight species JMs are easily that big, and many cultivars attain pretty impressive caliper with age.

LOL!! Ken, you need to get out more. As Sara notes, Japanese maples can reach some significant size with age.

And I have to question concerns about tree structure. Tight crotch angles are very common with JM's and typically of minimal concern. I have yet to see one fall apart or fail as a result.

It may very well be wetwood/slime flux...it could also just be the draining of excess moisture that has accumulated in the crevice between the two trunks. If it has a strong odor, it is probably slime flux as that is essentially fermented sap. Swabbing out the area with a rag dunked in isopropyl alcohol or a dilute beach solution may help with keeping down the odor and deterring the insects that might be attracted to it.

while i dont disagree with what you said ... i can NOT agree with it ... BASED ON THESE PIX ... ergo ... i asked for more pix.. to offer better guidance ... and i surely wouldnt worry about a large JM .... if its structurally sound ...

perhaps the situation requires more than a antiseptic swab ...

sorta like.. without getting too gross.. like breaking your arm ... and stopping the bleeding.. but not really worrying about whats really going on .. yeah.. a bit dramatic...

i just want to give the poster the best advice/value for the money paid for the advice ... lol ...

ken

ps: saying that i need to get out more.. might be the understatement of the century.. and we are only 19 years in ... rotflmbo ....