hard/hissing brakes on 86 4000Q

[Huw Powell]

sounds like his vacuum brake assist servo (big rubber diaphragm in the
round thing behind master cylinder) may be shot... unless he's lucky and
somehow there is a leak in the line to it.  But I can't figure out how a
leaking line would make these symptoms.

Try undoing the vac "feed" line to the servo and applying suction, see
if it holds or "hisses"...

Stephen Ankney wrote:
> 
> Listers,
> An internet friend is having problems with his brakes. His pedal is
> extremely hard to depress and when it is depressed it makes a hissing sound.
> Any ideas? Thanks! Car is 86 4000Q...

-- 
Huw Powell

http://www.humanspeakers.com/audi/

http://www.humanthoughts.org/