Look at the year of the vehicle the vin for sure and figure out when the box was put on it. It will be either a Chevy or Ford. So that the year and say Ford which will be a F53 chassis to the place you deal with and if possible take the item and you can usually get it right.
Brakes yes they should be check. Ours last gas was a 99 38 foot , just over 24000 loaded. You touch the brakes you felt it. Brake pads and rotors are not that hard to find. They glazed over just like a car. You also need to get into doing a full brake fluid bleed. Suck out the master brake fluid and fill in with new and then each bleed each wheel till you get clean and new fluid at that point. Ours was done every two years with a high end fluid. Made a lot of different. Also check your rubber hose on the brakes. If they have not been replace it way past time. The can and do separate inside and can cause issues. Auto transmission fluid need to replace every few years also if driving in the Mountains or hills. Again ours was either 2/3 years due to where we live. Not sure how much you weigh in at but that something you need to know. Yell when you need something. Someone is always here. Welcome to the Forum.