If your rear brakes are "soft" you probably need an adjustment on them. As far as the front left line, you either could have a bad caliper or a bad brake hose which could be clogged. I'm leaning towards the hose. Are you sure you don't have any other leaks? Are all of your bleeder screws good? Brake boosters and master cylinders rarely go bad but they can but be positive and hope that it isnt.
It possibly could be you're screwing up the sequence on how you should bleed the system especially after since you replaced the MS. The proper sequence on bleeding all 4 wheels are: Rear right, Rear left, Front right, and Front left.
Anytime you mess with the MS or the proporting valve all 4 have to be bled which is what you are doing. That is the proprer sequence becuase you have to bleed farthest away from the MS and then work your way to it. Try the process again like I told you and it its still the same you might have a bad brake hose or caliper up front or a bad wheel cylinder in the back. Hope this helps and let me know how it goes. Thanks.
Sunday, January 25th, 2009 AT 7:14 PM