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2003 Ford Master Cylinder Failed Twice in 5 Months

I have a 2003 Ford Escape 3.0l V-6. In June while driving to a job interview, my brakes unexpectedly failed. With absolutely no warning, the pedal went straight to the floor. I replaced the master cylinder…problem solved. 5 months later, driving to the gym, after stopping successfully several times with no mushiness in the pedal, at an intersection, the pedal goes straight to the floor…no stopping power.

I can’t remember if the brake light came on last time. This time it did. Both times the fluid in the reservoir was full and looked to be relatively clean. Both times there were no apparent leaks in any of the fuel lines, abs module, at the cylinder, etc. I’m no slouch when it comes to car repair. The master cylinder replacement was done correctly, the lines were bled properly.

I have my own theories but I don’t like any of them as my car rolls properly at idle, my brakes have not, nor do they currently make any noise or grinding sounds, and the pedal goes all the way to the floor. Your thoughts?

If you pump the brake pedal, does it build up pressure in the system? Have you tried bleeding the lines again?

check to see if the brand of master cylinders have a flaw, try a different store to get one. I have seen this happen several times with parts. I would get it at a certain store and have to replace it with another one from same store, then eventually get money back and go to different store and it works fine. Some stores carry a cheaper made part that regularly have recalls. Just a suggestion.

With a 2003 car with ABS brakes and track control the brake fluid should be changed every 3 years, that would be 3 times and due for a 4th change. How many times was the brake fluid changed since the car was put in service? Was the fluid changed when the master cylinder was replaced?

Old and contaminated brake fluid could be part of the problem. Make sure it is good fluid DOT 3 or 4 as specified for your car.

@mleich - No, pumping the pedal does not build pressure.

@Shannon - If this hadn’t happened twice in such a short period of time I could buy that. However, given the way this has happened so similarly both times, I’m not in love with the faulty part theory. Also, there was a major recall of master cylinders for this vehicle in 2007 I think. The likelihood that bad or faulty parts still exist is low. I also purchased from a reputable auto shop, I don’t believe they would intentionally pass bad product.

@UncleTurbo - The fluid was changed with the last master cylinder install and replaced with DOT3 as specified.

Did you bench bleed the master cylinder before installing it?

Of course.

@Pberard2002, that’s good.

Some guys don’t always do it.

By the way, how are you going about bleeding the brake lines afterwards?

I use a diaphragm brake bleeder and the power probe BA03 adapter.
I work on fleet vehicles and there’s lots of Fords. I use my own personal adapters, because it’s a PITA to find someone else to step and hold the pedal, etc.

http://store.powerprobe.com/static/c-brakebleederadapter.php

Is the pedal freeplay adjustable?

If the pushrod to the master cylinder is too tight the feed from the reservoir won’t work correctly.