gs450h clunking from front brakes

[carnut1980]

Hello.

My 2007 gs450h makes a metallic knocking sound from the front brakes. It is more prominent when I move forward slowly,  then brake, then reverse slowly,  then brake,  etc, as opposed to during general driving at speed.

It doesn't sound like worn bushes.  It has a higher metallic pitch.

Front pads and discs are new. But the sound was there before I changed them anyway. 

Please see attached video and have a listen. It's driving me nuts. 

Cheers 

20170904_133321.mp4

[Britprius]

I cannot get that to play, but the usual cause of a slight knock from the brakes is missing anti rattle shims. If the brake pads have any free movement in the direction of travel of the disks when the brakes are applied the pad rotates with the disk until it hits the caliper body.

jack the front of the car up, and get someone to hold there foot lightly on the brake. Try turning a front wheel backwards and forwards if you hear a slight knock that is the problem.

John.

[carnut1980]

Cheers.  I'll try and see what the issue is with the vid playing. 

I have had cars with missing anti rattle shims,  they made tinny noises when driving along,  particularly over speed bumps. 

I have to say this doesn't sound like that.

But I will jack the car up and have a look round 

[Shahpor]

Just to say that I managed to view the video without any problems.

John, in case you weren't aware, you can use a program called VLC media player to view mp4 videos.  It is very good and I have rarely come across a video it couldn't play.  You can get it here:

https://www.videolan.org/vlc/download-windows.en-GB.html

As for noise, I agree it is a strange one.  I currently have a clicky noise from my front brakes which sounds like shims, and it sounds nothing like what you are experiencing Jeremy.  I am not sure what to suggest other than I am very curious to know what is causing it.

[carnut1980]

Cheers shahpor, i will take the front wheels off in a couple of weeks when i am off work, and try johns method, though i very much doubt it has anything to do with anti rattle shims