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Brake pedal goes to the floor. Why?

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Old 03-31-2018, 10:21 AM
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Default Brake pedal goes to the floor. Why?

Today as I pulled into my in-laws driveway I noticed the brake pedal went all the way to the floor. It slowed down initially, but when I went to apply more pressure to the brake pedal to stop the vehicle, it simply went on through to the bottom.

In the past 9 months I’ve had the brake fluid changed. My 1999 A6 quattro has over 266,000 miles on the odometer.

Any idea what’s going on with my brakes?
Old 03-31-2018, 10:38 AM
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How's your brake fluid level? If it's going down, look for a leak in one of the lines. If not, you may have a bad master cylinder.
Old 03-31-2018, 11:27 AM
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There is a test for that via VAGCOM, involves pumping up the break and then testing the pressure held via VAGCOM. Check Rosstech for details.

ESP System Function Test - Ross-Tech Wiki

Mike
Old 03-31-2018, 01:50 PM
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Default Now the Brake light is flashing!

Originally Posted by georgeb944
How's your brake fluid level? If it's going down, look for a leak in one of the lines. If not, you may have a bad master cylinder.
Now this wonderful brske light has come on in the dash and it flashes and makes a singing noise to boot!
Old 03-31-2018, 03:40 PM
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What george said. If fluid level is ok then hook up VAG Com for error diagnosis.
Old 03-31-2018, 05:15 PM
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Default Leak in Right Front Wheel Found!

Originally Posted by Harleyguy
What george said. If fluid level is ok then hook up VAG Com for error diagnosis.
I stopped by my local O’riely Autoparts store and the tech had me start the car and pump the brake pedal. I then backed up and sure enough, there was a puddle of fresh fluid on the concrete and there was brake fluid on the rim (see pics).




Now ny question is on how to replace the brake Lin to that right front tire. Should I replace the other lines at the same time?
Old 04-01-2018, 12:49 AM
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Before you start buying parts to replace, you should do a bit more diagnosis. Jack up the front of the car, use jackstands, remove the wheel, add fluid and have a helper press on the brake pedal while you observe the source of the leak. It might be a hard line, or a rubber hose , or a connection. Depending on what you find, you should check the other lines for similar problems. Resolve those as necessary.

A good shop should.be able to do the job right.

Last edited by georgeb944; 04-01-2018 at 04:08 AM.
Old 04-01-2018, 09:48 AM
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Thanks for the suggestions. I’ve had good luck at my local VW dealearship. I’ll see if they can look at it Monday.
Old 04-03-2018, 04:53 AM
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Replace flex brake lines on both front wheels at this age. Make sure caliper is not leaking, but I'll bet it's the lines. Did mine this year. Easy if you spray Pblaster on fittings before unscrewing. Use special tool (golf tee) to plug hard line so you won't loose much brake fluid. You will have to bleed each caliper. I have a hunch that you will have a shop do it, though.
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