brakes wont work

[william64744]

i replaced the master cylinder because there was no brakes nothing no leaks just pedal went to the floor still stoped but not very well. after i replace ythe master cylinder i can not get it to build up pressure the master cylinder is working put the pedal still goes all the way down no air in the lines i bled all the wheels there not anymore
air it has hydroassist is there a special way you have got to bleed this type of sytem thanks

[silicon212]

Originally Posted by william64744

i replaced the master cylinder because there was no brakes nothing no leaks just pedal went to the floor still stoped but not very well. after i replace ythe master cylinder i can not get it to build up pressure the master cylinder is working put the pedal still goes all the way down no air in the lines i bled all the wheels there not anymore
air it has hydroassist is there a special way you have got to bleed this type of sytem thanks

Did you bench bleed the master cylinder after you installed it but before you connected the brake lines?

[william64744]

yes thin i also bled the brake lines at all 4 wheels

[UnexplodedCow]

sounds like you have a leaky brake line.....check around the car. I had a wagon version do that to me once....at least it was in my yard.

[william64744]

I checked for leaks with all the wheels off nothing its not using any fluid

[silicon212]

Originally Posted by william64744

I checked for leaks with all the wheels off nothing its not using any fluid

There should be a pushrod in the power booster that makes contact with the pistons on the master cylinder. Did you check to see if that's there? It will have a ball or rounded tip.

[william64744]

yes and it moves like it should

[UnexplodedCow]

Did your lines bleed well? Were they plugged, maybe? Just some thoughts. Another idea is that you have a defective master...see if you can get another in return....maybe it'll work.

[BZR77CHEVY]

I had this type of problem a few years back on an 80 4dr. For 2 weeks I played around with lines then calipers and wheel cylinders, the metering valve, and Booster only to figure out that the rebuilt master cylinder that was less than 3 months old was bad. I took the one off of the 77 caprice that was waiting for an engine transplant... problem solved.

[william64744]

i drained all the fluid out and then filled the resevor and pumped all the fluid out until it came out perfectly clean then pu it back together it works know