This is a subject we've been discussing in rustyshackleford's thread about the problems he's had with his new 5E series tractors. I have had a similar problem with my new tractor.
Simply stated, when I push the brake pedals on my 2014 5075E tractor, they go straight to the floor and do not provide enough braking to stop the tractor. With the second and subsequent pushes, the brakes work nicely. If I don't use the brakes again within a few seconds, the pedals go to the floor again. My dealer and apparently John Deere also, say this is normal and within specs for my tractor.
I'd like to get an idea how many other owners of the 5055E, 5065E and 5075E tractors of model years 2013-2015 are experiencing this problem. This forum is just a start, as most owners do not participate here, but it should be a good place to begin. I don't know if this problem is specific to the cab models and will be interested to learn more from your responses.
I intend to address this problem directly with John Deere, as they have apparently limited the amount of support they are willing to authorize my dealer to provide; it took several weeks for my dealer to get authorization from JD to come out and test the brake system pressure, and that's apparently all they gave him the ok to do. My dealer has been very responsive to my needs , but without any instructions or reimbursement from JD, I understand why he cannot provide any further help with this problem.
The legal advice I got is to gather as many other owners as possible to join in my claim. I am also going to contact OSHA for help and if necessary, the state's attorney general's office. My tractor is not safe to operate. My insurance carrier has assured me I would be covered in the event of an accident but that with the information I've provided so far, they would subrogate any claim against John Deere. I have the impression JD is ok with that and can only guess it's because finding and implementing a solution to the problem would cost them more.