Left Caliper is leaking

[bs175dths]

Clean and check again to make sure it is not the left fork seal first.
Perhaps tying a rag around the fork seal and then bouncing it or going for a ride would be a good way to check it too.

Some time ago I thought my differential was leaking but it turned out to be a leaking rear shock.

Likewise a leaking clutch slave cylinder turned out to be a stator wire plug leaking on the rear case.

Sometimes it is not the most obvious item that is actually the problem.

I am glad you said a rag and not a diaper! ~O)