JD310A breaks making noise worse in reverse

Hi everyone I just got done rebuilding jdb injector pump for the first time with complete and total success Now the brakesI need to fix they are making like a chattering when I use them and more so in reverse can anyone one tell me how extensive it is to get to the brakes and inspect them I have heard that bad brakes can lead to disastrous problems with this system learning as I go so I don't know much about the brakes system Thanks for any help jon

JD310A breaks making noise worse in reverse