Repairs GX 345 Hydro Brake Peddle/lever will not release all the way

Gentlemen I bought a used 2001 JD GX345 hydro drive and guy told me the brake peddle or lever will not release all the way. As you know you have to push it in to start the engine and when you release it will not return all the way up and you have to pull it up with your hand otherwise it is like driving with the brakes on. Any idea what caused this, don't see any return spring. Looks like where the rod goes through a sleeve type support under the undercarrage cover it could be binding due to rust or degree. Any help appreciated, thanks