I have a 2001 GMC 1500. Sometimes when applying brakes,my brakes pulses,all the way to the foor and doesn't want to stop me. No lights are on. And no code are coming up. Have new brakes.

sounds like ABS sensor , check master first ,the way I do that is in park and apply slight pressure to the pedal and if it makes it's way to the floor thats a sign of bad master .I'm not a technician but if your pedal can go to the floor that does not sound safe and perhaps a technician shopuld look at it .

It means there's air in the brake system, u need to bleed the brakes one wheel at a time. Have someone pump brake pedal 3 times, hold it pressed while someone turns the bleeder fitting loose, once it squirts fluid out, repeat 3 times on each wheel, refill master cylinder as u bleed each wheel and keep master cylinder closed while bleeding system