Air sound on break pedel

SOURCE: press pedel makes air swishing sound but no power

The power brake booster, is not holding vacuum, that's the hissing noise you hear, and that's why you don't have power brake's, the only fix is replacing the booster.

Testimonial: "Thank you, didn't know if needed to replace master cylinder also??"

SOURCE: proper way to bleed brake lines and system

First check your level in the brake fluid reservoir. If full, then you will need to pull off one tire at a time to bleed the brakes. There will be a bleeder valve on each caliper. Open the valve and pump the brakes until hard and hold, to get air out of the system. Then close the valve. I usually use a clear tube attached to the valve so that I can make sure I got all the air out of the line. Once air is gone, do the other side. Make sure to keep brake fluid full in reservoir to prevent air from reentering the brake lines.

SOURCE: when bleeding brakes have good pedal with engine off. with engine running pedal goes almost to the floor what is wrong

can you here a hissing sound when you push the brake while its running? if so then you have a bad brake booster, need to replace it, the hissing is actually the vacuum that builds within the booster escaping thru the seal in the booster