320i - Hissing brakes

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ZARS
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Tue May 14, 2013 12:24 pm

Hi folks

The car seems to have developed a hissing sound when pressing the brake pedal.

When switched off the pedal seems hard and with engine on the hissing comes from the glovebox area every time the brake pedal is pressed. Braking seems a little less effective than before (car has uprated discs at the front / drums at rear). Fluid level is spot on.

So, could it be a vacuum leak or is it likely to be a wallet buster?

Cheers :hammer:
BMW E30 320i coupe
Porsche 951
Merc W203 C180K
Saab 9-5 SE
Rtaylor2208
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Tue May 14, 2013 12:41 pm

There is a vacum pipe (on my 325i at least) that runs from the brake servo to the throttle body. I would check there for a split.

Hopefully they are OK as from the dealer if its the two pipes setup that goes into the TB then they are over a £100 for a replacement.
milescook
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Tue May 14, 2013 12:42 pm

http://www.e30zone.net/modules.php?name ... ght=whoosh

and

http://www.e30zone.net/modules.php?name ... ght=whoosh

You're problem was incorrectly identifying the sound as a hiss, when it is infact a whoosh! :D

Happy to help ;)

Also, for the brakes seeming a bit less effective, this could either be in your head which is perfectly reasonable when you start hearing noises, or something else but I'm not experienced enough there to advise.
The story so far... http://www.cookracing.co.uk/

Also please help the race budget by watching some videos :) https://www.youtube.com/cookracinguk
ZARS
E30 Zone Newbie
E30 Zone Newbie
Posts: 52
Joined: Tue Feb 05, 2013 11:00 pm
Location: London

Tue May 14, 2013 12:46 pm

Yes indeed, a whoosh :mad:

So, seems like I can ignore it, well for the short term anyway.

I will check the pipes though just in case. Just broke a 318, could have used the bits from that if possible but it's gone now. Damn!

Thanks fellas 8)
BMW E30 320i coupe
Porsche 951
Merc W203 C180K
Saab 9-5 SE
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