No brake pressure when car is started! PLEASE Help.

I went ahead and replaced my calipers, rotors and pads. With doing so I disconnected my brake lines from the brakes. I then went ahead and put the system back together and then bled the brake system after everything was intact. At no point did I depress the brake pedal when the braking system was not fully put back together.

After bleeding the brakes with a speed bleeder and then by hand to make sure I started the car up. Guess what... No brake pressure. So I then shut the car off and pumped the pedal 4 times. Brake pressure is now back. I then start the car again and no brake pressure... This seems to happen immediatly when the car is started that I lose pressure.

I then assume its the master cylinder, so I replace it. I followed the bench bleeding to the "T". I then bleed the system again and the same results happen again.

I then have one guy bleeding, one guy pumping the brakes and one guy watching/filling the master cylinder. The guy at the master cylinder says that he can hear air getting pushed out of the master brake cylinder, but it doesnt sound like its sucking any in to the master cylinder. But he says he can see the fluid lowering as we are bleeding the system. I am the one releasing the brake bleeder valve and all bubbles are removed from the system.

What would cause the brake fluid in the master cylinder to bubble due to air escaping through the master cylinder???

Thanks for any help provided!!

Kendall

i believe the bubbles from the master cylinder is normal its a valve thats doing that when you depress the brake pedal. just make sure when you bled the system you start from rr,lr,fr,fl. or even get a manual to make sure thats the correct bleding sequence not all cars can use that bleding sequence. all check all your hoses to make sure none are leaking or pulling in air.

also you said yoou changed calipers also you might want to double check to see if the calipers are on the right sides. i made that mistake once and had pretty much the same symtoms you are having.

hope this helps

I checked everything else... i guess I could have put the calipers on the wrong side... I will see if that is the case. Never knew it mattered.