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Discussion Starter #1
I just finished bleeding my 05 automatic FF brakes using a one man bleeder kit. Started with RR, RL, FR, FL sequence. Drums in the rear bled fine, and FR was also ok. When I got to the last caliper, I noticed lots of air bubbles after opening the bleeder nipple and pressing the brakes 3-4 times. Kept replacing reservoir and never let it run dry and kept pressing brakes to try and let all air out. I finally stopped when it seemed like no more air was in there and put everything back together and topped the reservoir. I took it for a spin and brakes do not seem any tighter although they do stop. I also noticed a hissing sound when I depress the brakes when I am in P, but can't hear the hissing once I start driving. Anyone know what this may be caused by? Is there still air in the system? Should I re-bleed from step one? Any help will be greatly appreciated!
 

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As you mentioned, you had air bubbles when bleeding the front caliper - the bleeder nipples on the front calipers may be slightly smaller than the bleeder nipples on rear drums and you could be introducing air when you bled the front brakes. I notices this issue on my 05 but not on my 07. If you were using the same tubing on all four brakes, I would try re-bleeding the front calipers and zip-tying the tubing extra tight. If that does not do it for you then a failing master cylinder could bu the culprit.
 

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2004 Focus Wagon, Zetec DOHC, Auto
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One trick I learned about how to prevent the reservoir running dry is to turn the can upside down in the reservoir. It will supply fluid as needed. Make sure top of can is clean if doing this so that it does not contaminate the reservoir.

Another thing about brake fluid...it ruins paint. If you spill any, wash it off with water ASAP.
 

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Discussion Starter #4
As you mentioned, you had air bubbles when bleeding the front caliper - the bleeder nipples on the front calipers may be slightly smaller than the bleeder nipples on rear drums and you could be introducing air when you bled the front brakes. I notices this issue on my 05 but not on my 07. If you were using the same tubing on all four brakes, I would try re-bleeding the front calipers and zip-tying the tubing extra tight. If that does not do it for you then a failing master cylinder could bu the culprit.
Good point, the bleeding screw was definitely a wee bit smaller in the front which almost caused me to strip the nut. The nipple could definitely be smaller. I always thought that if air got into the system, you had to start from the beginning? Is it ok to just re-bleed the front calipers?
 

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Discussion Starter #5
One trick I learned about how to prevent the reservoir running dry is to turn the can upside down in the reservoir. It will supply fluid as needed. Make sure top of can is clean if doing this so that it does not contaminate the reservoir.

Another thing about brake fluid...it ruins paint. If you spill any, wash it off with water ASAP.
That's actually a very good hack! Wonder if I could just partially remove the seal to at the lip to prevent major spills. Thanks.
 

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The hiss makes me suspect a bad power brake booster. You need to vacuum test the booster to verify its condition. A booster that is leaking vacuum will absolutely affect braking power.
 

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Discussion Starter #8
The hiss makes me suspect a bad power brake booster. You need to vacuum test the booster to verify its condition. A booster that is leaking vacuum will absolutely affect braking power.
The braking power seems ok. I ran the test where you pump the brakes while the car is off, turn on, then felt for the brake depression once the car starts. That checked out fine. Is the hissing sound tied to only the brake booster or is it possibly the air that could still be in the brake lines?
 

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oh- well if the braking power seems ok, then you are probably ok. I assumed you had soft brakes from air in the system and/or bad master cylinder. A little hissing sound sound is okay when pumping the brakes.
 
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