[chevyguyase]

Are you bleeding the brakes by pumping the pedal? If you have trapped air in your system, when you release your brake the fluid will return to the master cylinder rapidly. This will cause the fluid to squirt up against the lid. The air in the system will compress, fluid will not. The fluid should not be high enough to leak out. once you bleed the brakes I think your problem will be remedied. If you ran your M/C empty when you bled it, you may have to re- bench bleed your M/C. You mentioned you still have to bleed the brakes, If you are using gravity, pressure or vacuum bleeding this does not apply to your situation.