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Discussion Starter #1 (Edited)
Slow brake booster?

Hello everyone

A few days ago I had the break discs and pads exchanged as well as changing to braided BF Goodrich hoses on 2004 156 2.4 20V. I had the system refilled with DOT 5.1 brake fluid and bled at least two times.

After first drive I was immediately able to feel the difference in terms of pedal feel. Yet I had the impression that sometimes the pedal is kind of inconsistent. For example I was braking normally towards a junction and then I could feel that the pedal travelled a bit further downwards after a few seconds of being stopped. Until then I was thinking that there is probably still a bit of air in the system.

However the next day I drove it out of the garage and when I wanted to brake for the first time, I had a rock hard pedal with basically no travel and braking effect. It was as if the vacuum servo would have failed. Yet afterwards braking was normal again not matter what I've tried, as if nothing happened.

Today I tried pumping the pedal with the engine off until it was hard. I then fired her up with my foot on the brakes and it surely took more than 10 seconds until the pedal reached its final position. Thus it seems as if it is not able to generate the vacuum fast enough. :confused:

Now I would be very glad if you guys could give me any ideas on what is happening with my bella 

Thanks and cheers!
Marco
 
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Split vacuum hose or hole in diaphragm, or damaged seal to the brake booster/ vacuum hose clip;)
 

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Discussion Starter #3
Split vacuum hose or hole in diaphragm, or damaged seal to the brake booster/ vacuum hose clip;)
Well I brought it back to the garage who installed the braided hoses. They have rebled the system and checked the servo for leaks and couldn't find anything wrong. However now I have the impression that the inconsitent pedal feel has dissappeared completely and the phenomena with the missig brake boost has since never reoccured. Also if the pedal is pumped with the engine off, it now reaches its 'regular' position much quicker when turning it on.

I keep thinking that if there would be a leak, I'd keep getting problems more regularly?
 

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My brake pedal used to creep down under foot pressure; replacing the brake lines with stainless braided and changing the fluid cured the problem.

Fluid should be changed every two / three years, but how many of us do so?
 

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Discussion Starter #5 (Edited)
Before I started the car, the brake pedal was hard. After turning the engine on, it took about 5 seconds until the pedal started moving down to its regular position. What do you guys think?
 

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Discussion Starter #6
Just a quick question: I know it's normal to hear a woosh sound when depressing the brake pedal (as soon as the pedal moves) with the engine OFF because of air entering the booster. However if I do the same while the engine is running, it is still making the woosh sound every time I depress the pedal?
 

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Just a quick question: I know it's normal to hear a woosh sound when depressing the brake pedal (as soon as the pedal moves) with the engine OFF because of air entering the booster. However if I do the same while the engine is running, it is still making the woosh sound every time I depress the pedal?
leaking servo
 

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Discussion Starter #8
Thanks mate! So it seems :(

Here is a quick video I've made that first shows the wooshing noise with the engine off and then, starting from about 0:15, with the engine running: Alfa 156 2.4 20V Brake Servo Noise - YouTube

While filming the video, I have also noticed that the brakes are sticking (car not rolling freely). Is this also related to the servo issue, or is this a different problem altogether?
 

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Discussion Starter #9
Since these problems appeared directly after having the brake fluid changed, I am wondering if the mechanic who did the work can be held liable. Especially as they told me that they have fully emptied the system prior to refilling and that they bled manually by foot without switching the ABS unit.
 
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