Brakes Not Working After Brake Line Replacement - 69 Camaro

[rockphil]

I replaced the brakes lines on my 69 Z28 (front disc/rear drum) during a restoration of my undercarriage. I did not remove the master cylinder or power booster nor did I drain the fluid from the master cylinder. I simply removed the old lines and installed new lines. The lines were bled in the typical fashion starting with the rear brakes and working to the front brakes. After extensive bleeding - the front calipers aren't moving at all when I depress the brake pedal. The pedal bottoms out without any resistance to speak of.

Any Suggestions?

[Damon]

Rockphil,

I had the same problem on my car in the rear.  No visible leaks anywhere.  It was not until I used the little handheld vacuum bleeder that I discovered my problem.  The vacuum gauge would pump up to 25lbs and was all air for a bit, then fluid full of air bubbles.  At that point I realized I was sucking air and while I pumped the bleeder my son could hear the hissing noise up front by the master.  I traded spots with my son and while he pumped I squirted a drop or two of 30 weight oil around the master cylinder fitting for the rear brakes and my son said the air was gone and vacuum held steady.  Once we had it bled, I started the car and my son pushed the brake pedal down with the vacuum boosting and sure enough the "new" brake line was leaking fluid.  Cut the end off and had a shop put a nice new flare on it today, will try again tonight.  I would do the same thing up front on yoru car, one of your "new" lines might be leaking.

Good Luck,

Damon

[JohnZ]

After extensive bleeding - the front calipers aren't moving at all when I depress the brake pedal. The pedal bottoms out without any resistance to speak of.

Any Suggestions?

Did you make sure to maintain fluid in both reservoirs while you were bleeding? If the pedal bottoms out, you either have air in the lines or the piston seals in the master cylinder have failed.