e34 540i brake issue?????

[longdom]

just when all was going good, i have another damn problem, now its the brakes...i replaced the discs, with brembos, i replaced th epads with akebono ceramic pads and changed the sensor too..2 days all good, then....
when i brake, i hear knocking sound from underneath, from brakes, cause i can feel in pedal too.
get the mechanic to check everything again, just in case something not done right, but all good, put discs on machine to test them, and find one disc is only slightly warped, but only slightly...could this be causing the knocking noise, and vibration??????
the mechanic is bewildered...all is good, nothing is touching or rubbing against anything, and brakes were fitted perfect, they were also the right size and all for my car...can anyone help me here???????????
does anyone have the same problem???
mine is a 1994 e34 540i m60 V8 engine, euro model..

[witeshark]

It's hard to be sure, but I'd guess that even a slight warp may well be the cause.

[marti5]

slight warp would cause more of a judder, a knocking would point towards caliper bolts, I replace mine every time I replace my pads.

[emiliomax]

i would have to agree with Marti. You probably have a combo of both. Best of luck

[emiliomax]

And what I meant with both was the warped disc and the bolts. Precision engineering

[longdom]

thanks guys...
caliper bolts???
now thats a new one..wouldnt i see some wear on inner rim?
or somewhere, cause a knocking sound means something is hitting, so there has to be a mark somewhere???
mechanic cant see anything..
and this noise also knocks as wheel turns, so is repetitive with turning of wheels, only on braking though, and i hear and feel it only before stopping at slow speed.

[longdom]

i believe that a warped disc, even if only slightly, will give you pedal shudder like you say, not tapping, knocking sound.

[marti5]

Bolts, or your ceramic pads are jumping about in the caliper, but youve had the caliper off to change the discs, always use new bolts after removing the caliper.