afzalk72

Hello every one !

When in reverse My 2006 525xi 106k has front passenger side clunk or thumping noise as soon as I slightly hit the brake to stop. Its not frequent. It happens only once if the car is cold and sitting for few hours. Car had been in garage several times and mechanic said every thing in front-end is tight and normal also he re-adjusted front brakes and rotors. It's very annoying and cant seem to find where its coming from.

Has any one experienced this in thier e60??

pcy

There may be some 'play' in the brake pads and when you start going in reverse and tap breaks, the pads are moving in the reverse direction (in that extra gap).

If that's not it, check the trans mount.

afzalk72

Thanks for the reply PCY..

if there is a 'play' in brake pads is this normal or do I need new brake caliper, cause my mechanic already re-adjusted the brake pads, also can you explain more whats trans mount.

Thanks

pcy

Transmission mount degrades over time and allows trans/drive shaft to flex enough to make noise. Have your mechanic check the condition of the transmission mount and flex discs (flexible rubber plates at the end of shaft) on the drive shaft.

Normally, there shouldn't be any 'play' between the pads and caliper. There is really no 'adjustment' one can do to the rotors or brake pads - if they are all seated and bolted properly. One possibility is that if the pads are generic/aftermarket pads and they are not EXACT size of OEM pads, then you can expect some play.

In the attached diagram, pars labeled 1, 2, and 3 are part of transmission support/mount.
In the other diagram, part #2 is the flex disc.

If you are near Nashua/Tyngsboro, I can take a look.

afzalk72

Thanks for detailed reply PCY, my mechanic told me that he replaced all four brake pads and rotors, so since last fixed I have heared the clunk noise only once, I am hoping this is it, if not may be you can look at it and I live in Nashua.