What type of braking system does the A/S32A-31A tractor use?

The A/S32A-31A tractor utilizes a hydraulic wet disk braking system specifically on the rear wheels. This design is advantageous because hydraulic systems offer superior responsiveness and modulation compared to mechanical systems, allowing for smoother stops and better control. The wet disks are housed in a fluid environment that helps dissipate heat, enhancing the system's longevity and reducing the risk of brake fade during prolonged use.

In this particular case, the choice highlights that only the rear wheels are equipped with this hydraulic system, which can help improve traction and stability, especially in towing operations typical for this type of equipment. The front wheels may have a different braking configuration, which is compatible with the tractor's design for operational efficiency.

The other options describe braking systems that do not align with the established specifications for the A/S32A-31A tractor, such as mechanical drum brakes, air brakes on all wheels, or a hydraulic wet disk system on all wheels, each of which presents different operational characteristics and uses that are not applicable to this tractor's design.