While bleeding the brakes, there was an air sound when the pedal was pushed?

STUMPEDACCORDOWNER

MEMBER
2010 HONDA ACCORD
V6
2WD
AUTOMATIC
156,000 MILES

I just replaced the rear calipers and pads on my car. Bled the system. While bleeding, there was an air sound when the pedal was pushed. Pedal can be quickly pumped up and brakes respond, but then next time the pedal goes to the floor and no brakes at all. Master cylinder is full and there is no air in the brake lines (triple checked with clear stream of brake fluid at rear calipers.). Vacuum lines to booster seem okay. Air sound doesn't seem to be coming from booster. Hard to pinpoint this air sound from the pedal. Stumped.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

I need you to try something. Pump the brakes up so you have a pedal and then hold pressure on it. See if it slowly goes to the floor.

If it does, replace the master cylinder. I realize there was likely no issue prior, but when the pedal goes to the floor, there can be corrosion in the Master Cylinder which damages the plungers. This is the result.

Take a look at this link. Let me know if you feel the Master Cylinder is the likely issue. If it is, I attached the directions below for replacing it.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Let me know if this helps or if you have other questions.

Take care,

Joe

See pics below.

Images (Click to make bigger)