Well it suggests a leak. you should be able to find a puddle if you lost all that. Also could be a loose fitting, you'll just have to look until you find it.

The only other thing is it could be perhaps leaking into the booster....?

I suppose there could be a bubble that has moved up to the MC but seems doubtful if you drove it some distance to get it home.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.