Low brake pedal pressure

my girlfriend has a 95 4 door acura integra that i just changed the front brakes to, and when i hopped into the car 2 hours later, there was barely any pressure coming from the brake pedal. i changed the front brakes, i filled the brake fluid back up (but i didn’t close the cap) and then i pumped the brakes when the car was off… 2 hours later, barely any pressure. i know i did something wrong, most likely having to do with the cap to the brake fluid reservoir off when pumping the brakes, but i need certainty. help please??

Did you adjust the rear brakes? I’d start there. Also, check the front brakes for leaks. If the fluid reservoir went empty during the work you now have air in the system, and need to bleed all the brakes, starting with passenger side rear.

May I assume that the car has ABS? And, if so, did you press the caliper pistons in with the bleeders closed, forcing the brake fluid back into the ABS system?