My ABS cab has always made a quick "thunk" noise every time I put the keys in accessory and start the rig up. Ive read threads about ABS units humming and what not, but mine does not. I too have never had any problems with my brakes.

Is a simple replacement of the Cab going to solve my issue?

 

The noise you are hearing is normal. Its doing a self-check. If you don't have any ABS lights on and the brakes are working fine. So I would replace the CAB unless you have a main fuse code.

 

So are you saying it needs to be replaced or it doesnt? Im not quite understading what you're saying. This noise hardly sounds normal and is loud.

 

What he meant was if you don't have an abs or brake light in your dash on, and/or if the brakes are working fine then there is nothing to worry about

 

I have a hard time believing that this noise is normal.

 

You can try replacing the CAB and see if the noise is gone. Then let us know if the noise is gone.

 

Master tech knows his stuff, and yes the noise is there but if everything is working as it should then it comes back to the old saying "if it ain't broke dont fix it"