Copyright Goodheart-Willcox Co., Inc. 823 Chapter 24 ∣ Track Steering Systems steering clutch and brake based on the steering control levers and foot brake pedal are shown in Figure 24-15. On a traditional steering clutch and brake tractor, the machine can be held stationary by three different means: • Parking brake applied. • Service brake applied. • Both steering levers simultaneously pulled fully backward. Tractor Operation Steering Clutch Steering Brake Forward or reverse (straight path) Full pressure Full pressure Neutral steer 0 psi Full pressure Brake steer 0 psi Decreases to 50 psi Brake fully applied Foot brake applied Steering levers forward Full pressure Decreases to 0 psi Brake fully applied Torque converter in stall mode Goodheart-Willcox Publisher Figure 24-15. Fluid pressures applied to or released from the steering clutch and steering brake are listed based on the position of the steering levers and foot brake pedal. If the tractor is brought to a stop by pulling both steering levers fully backward, the torque converter will not enter stall mode because the steering clutches will be released. However, if the steering levers are moved completely forward and the service brake pedal is pressed, the torque converter will enter stall mode because the steering clutches are engaged and the brakes are applied. Brake housing Inner axle shaft Outer axle shaft Output hub Input hub Steering clutch Steering brake Retainer manifold Steering brake release pressure cavity Steering clutch pressure cavity Steering clutch piston Parking brake (application spring) Goodheart-Willcox Publisher Figure 24-14. A simplified illustration of a steering clutch and brake mechanism. The clutch is hydraulically applied and the brake is spring applied.