You have to remove the rear axl from the machine and split the axl casing to replace the brakes. I have an older JD 410 and it currently has bad brakes and will stay that way if you get my drift. The leaking injectors aren't too bad though nor too expensive and will make it run a lot better. I would guess $1500 - $2000 on the brakes and maybe $3-400 on the injectors for a dealer to do the work.