Banging brake pedal! Yikes!

[brobille]

YTA24V48 with GTRS800 transmission
My brake pedal is banging while idling or driving.
I've replaced all the pulleys and it still bangs away.
Any idea? Transmission? It's a GTR transmission

 

[ILENGINE]

Most likely there is a chunk of the drive belt missing.

 

[StarTech]

or a flat idler with a burned flat spot where the bearing had locked up and then became free again.

 

[brobille]

Most likely there is a chunk of the drive belt missing.

I'll check that, thanks ILENGINE

 

[brobille]

or a flat idler with a burned flat spot where the bearing had locked up and then became free again.

There was 4 pulleys in unit, I replaced 3, probably the one I missed :-(
Thanks for your post StarTech