A buddy of mine has on his 250 Mk3 troubles with losing brake fluid and doesn´t find where it leaks. All lines, fittings, calipers are dry. I suppose that the fluid maybe disappear into the brake booster. Always after 2 weeks there are missing some mm of the level in the reservoir. Does anyone know this issue?
I agree with what’s above. Check the clutch damper. Pretty easy to check, take off the passenger front wheel and look for any signs of leaking fluid. I had a slow leak and it ended up stripping the paint off the anti roll bar. If this is your issue HEL make a clutch damper delete which replaces the leaking part.