My friend was trying to change my brake pads in the front on my 1991 civic Si and I think he ended up draining all the brake fluid by loosening screw from the caliper connecting the brake line. Now when I start my car, there's almost no pressure from the brake pedal. If I try to pump it continuously, the pressure will not return to how it was before. All help appreciated from all the kind people.

 

try adding brake fluid then bleeding your braking system that will probably help