Changed master cylinder..now brake light comes on

I replaced my leaking master cylinder the other day and then bleeded the master cylinder. Then brakes feel like it brakes much better then before.
The only thing though is when I brake hard the brake light comes on.

I'm guessing I still have air in the lines and have to bleed the master cylinder again?

Also when I removed the reservoir I drained all the old brake fluid out and washed it out with water.I did allow it to dry but there might of been just a little bit of moisture left.Not much though. Could that have something to do with the problem?

bill302 said:

open master cylinder cap and visually inspect the float in the reservoir and ensure its working properly it should float on top of fluid and when the level in reservoir falls to a certain point the brake light is illuminated.what kind of calipers do you have on vehicle?

Click to expand...

I checked the float and it was low.Before I had filled the reservoir to about 1/4 to 1/2in. below the Max line. I just added to some brake fluid up to the max line and the floater started to rise.I took it for a ride and the brake light don't come on anymore.I guess that was the problem.

Thanks!