1quickZ28

Just finished upgrading my brake system, corvette calipers and an LS1 master cylinder. My problem is that after bleeding the MC as well as all calipers, there still seems to be air in the lines. With the car running, the brake pedal is very soft all the way to the floor. With the car running and I disconnect the vacuum line from the brake booster, the pedal feels very tight, like it normally would. Any ideas? Could I still have air in the MC? Or is my brake booster bad?

NOBR8KSS

iTrader: (12)

Sounds like the booster is good...normally a bad booster will mean a very firm pedal...not a soft one.

Did you bench bleed the master cylinder before installing it? If not, then you need to bench bleed to get air out of the master.

You could try rebleeding the entire system, but until you know the air is out of the master, you would be wasting your time.

1quickZ28

I did bench bleed the master cylinder, but I will pull it off and try it again! Then bleed the entire system. Thanks for the reply!

NOBR8KSS

iTrader: (12)

No need to pull it off again....just disconnect the the brake line closest to the "front" of the master cylinder (the high side). Connect the bleed kit to those and run the lines into the reservoir. Have a friend pump the pedal very slowly and make sure the lines stay submerged in the reservoir fluid. Once the air bubbles stop appearing, you can reconnect the front line and rebleed the four corners.

mitchntx

iTrader: (14)

When chasing an air bubble, bleed the lines just the opposite way you normally would ... LF, RF, LR, RR ...

You are pushing the air out, working it to the furthest point.

1quickZ28

Thanks for the advice, i'll give it a shot tonight!