Re: 535is brakes

[GToyama@xxxxxxx]

Bob wrote:

<<Hello,
    I have an 87 535is, and when the brakes are applied quickly the pedal
seems to have a lot of resistance for a second. The brakes do not apply
fully until the resistance gives way. This does not happen when the brakes
are applie slowly. Any Ideas ?>>

    Yup, BTDT.  You need a brake "bomb", the hydraulic accumulator that 
stores pressure the power steering pump supplies.  Rubber diaphagm inside the 
bomb is dead, and the pump can't provide necessary pressure immediately 
enough, hence the lag you feel in a quick brake application.
    You may also want to replace the filter in the bottom of the power 
steering fluid reservoir.  It can disintegrate, allowing fragments of the 
filter to get into the bomb and eat up the new diaphragm.  If the filter is 
already fragged, you'll need to flush the hydro system.
    If you need/want help in R&R'ing the bomb, feel free to email me.  I 
believe there have been recent posts re the procedure, and there are other 
BMW sites that provide such info as well.  I would estimate level of 
difficulty to be 2.5, where 1 is an oil change and 10 is an engine rebuild.  
It's just real messy, ATF all over the place, etc...

Good luck and Happy Bombing,
Gary

'88 535is
...many past Bimmers

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