Brake Master Cylinder Vent?

I just changed out all the brake system in my CJ5. I kept everything stock. wheel cylinders, kard lines, soft lines and MC. All new. I bled everything and adjusted the shoes. Cant wait to drive it. I installed a new set of seats and i got in to make vroom vroom sounds. Well i pushed on the brake pedal and it was stupid hard. Went in like a quarter inch and stopped. When i bled them the pedal moved great. Not sure what would have changed. Only thing i can think of is i have the cap on the MCm, but i didnt have it on when i was bleeding. Is there supposed to be a vent on the cap to allow for things to work? Just kind of odd that this is happening.

 

i will put it back on the lift and have a look again. The cap is what came with the MC so that is kind of why i asked about the vent. the cover plate is off and i can see if the push rod pushing a bit. i will get under it and see if something is off