Mechanics

BRAKE PEDAL GOES TO THE FLOOR BRAKES WON'T STOP

1989 Mercury Topaz • 240,000 miles

We have replaced master cylinder, front and rear brakes, calipers, cylinders and brake lines in the rear and bleed them still no brakes?
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Ktweety
September 27, 2012.




Something has not been done correctly. When bleeding the system are you getting pressure at all wheels?
Are you able to get pedal pressure when bleeding?

KHLow2008
Sep 27, 2012.
We are getting good flow from the dr front and pass rear but only trinkles from the dr rear and pass front. Before we changed the master cylinder it was opposite.
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Tiny
Ktweety
Sep 27, 2012.
System uses diagonal braking lines so one of the master cylinder circuit is not working correctly.

If you did not bench bleed the master cylinder, I would suggest starting from there. Get someone to slowly depress the brake pedal a few times and hold the pedal in a depressed position with about 10 psi of force, meaning the foot should not be held too heavy on pedal. Crack the inner line of the master cylinder and if fluids comes out without any bubbles, repeat with the other line.

Next we go on to the wheels and the bleeding sequence is Right Rear, Left Front, Left Rear, Right front. Do this with engine off.

If you are still having problem with insufficient pressure with Left Rear and Right Front lines, loosen the master cylinder holding bolts by 3 turns and repeat process. If it works, check the brake pedal and booster adjustment.

KHLow2008
Sep 27, 2012.
Thank u we will try that

Tiny
Ktweety
Sep 27, 2012.
Any updates?

KHLow2008
Oct 21, 2012.

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