2005 Suburban, 5.3 Flex, no options - 270k

In the last few days I have started getting a 'bounce' from the brake pedal.

Any thoughts?

 

I had that in my 01 Suburbin when i bought it at 130k. Never looked into it and it never got worse, just delt with it until I sold it at 190k.

sorry i didn't have an answer but at least you know your not alone! Good luck

 

do you hear the abs pump activating when this occurs?