I had to replace the 2 rear brake lines in my 98 Ford taurus,I blead the breaks and had peddle,Once I turned on the igination and started the car the peddle went to the floor,Do I now have air in the master cylinder? How do I bleed that, the brakes were fine till the line had broken.

steve lucash, October 2009

hi did you make sure that
A. the brakes were bled in the correct order, inc the fronts,
B. That no air managed to seep past the unscrewed bleed nipples.
C. are you bleeding with the engine running (this can help, but not essential).
D. that you used the correct grade replacement fluid,and that no water has got into the lines.
E. make sure the abs unit is working freely,and if it has a bleed nipple use it too.

I am not sure if it applys to the taurus but some cars that have brake compensators (fitted on the rear axle) need the car raised at the rear, with the rear road wheels, off the ground. then bleed the whole system. this is the only way to fully prime the compensator on such systems.

As for the servo itself, some do have a bleeds on them. but as long as you correctly fully bled the whole system at the wheels, and the servo is the original working one all should be good. note that brake master servos have differing push rod lenths (even across the same models) and if you inadvertently
replace the orginal for one that has a shorter push rod, you will see exactly the same issue as you are having .But as you did'nt mention replaceing it my guess is this will not be your problem.

Try bleeding again if you still run into problems it can only be a leak in the calipers/ cylinders or brake master cylinder piston seals.
hope that helps you get sorted out, best of luck

ian

ian, October 2009