94 trail Boss 250 Master Cylinder?

I am in the process of restoring a 94 Trail Boss 2 wheel atv. I acquired it with little or no brakes. I replaced the rear pads and have a working mechanical brake.
I put brake fluid in the master cylinder. Went to bleed the rear caliper first.
It does not seem as if master cyl. pumps much. Is there supposed to be a fair amount of pressure with bleeder cracked open? I did have the rear caliper off of atv for a repair. Before removal, I had a working brake light. Now the brake does not light up when handle on master cylinder is engaged.
With a bleeder cracked open at any given location, should there be a stream of fluid being pumped out when engaging handle on master cylinder?
thanks