when checking the trailer emergency brakes the tractor protection valve

One of the critical components of a semi-trailer is the emergency brake system. The emergency brake system is a crucial safety feature that helps with quick stopping in case of an emergency. The brake system consists of multiple components, and each component plays a crucial role in ensuring effective stopping power. One of those components is the tractor protection valve, which plays a pivotal role in releasing air to the trailer brakes when the emergency brake handle is pulled. In this article, we are going to focus on the importance of checking the tractor protection valve when checking the trailer emergency brakes.

What is the tractor protection valve?

The tractor protection valve is a crucial component in the braking system that helps maintain air pressure in the trailer brake lines. The valve is located in the primary circuit between the foot valve and the supply reservoirs. The valve's primary function is to maintain a stable air supply to the trailer brakes and prevent depletion of air in the system. When the emergency brake handle is pulled or if there’s a break in the system, the tractor protection valve releases the air supply to the trailer brakes. This ensures instant braking performance to the trailer in case of an emergency.

Why do you need to check the tractor protection valve?

Checking the tractor protection valve is an essential part of trailer safety checks, especially before the vehicle is put into service. The valve needs to be tested to ensure that it is functioning correctly and responding appropriately. This means that when the emergency brake handle is pulled, the valve should respond by releasing the air to the trailer brakes. Checking the valve periodically using the “T-check” procedures ensures that the valve is functional before it's too late to do anything about it. A faulty tractor protection valve can lead to brake system failure, which can be catastrophic.

How to check the tractor protection valve

The check on the tractor protection valve is simple, and it can be done through the following steps.1. Drain all the air from the system, including the supply reservoirs and the trailer brake chamber.2. Start the engine and build up the air pressure in the system. This may take several minutes depending on the size of the system.3. Once the air pressure reaches the cut-in level (typically between 100-120 psi), turn off the engine, remove the keys and step out of the cab.4. Pull the emergency brake handle, and the blue air gauge should show a rapid drop in pressure. This indicates that the tractor protection valve has released the air to the trailer brakes.5. Start the engine and release the emergency brake handle. The air pressure should go back up to the cut-in level.

Conclusion

In summary, the tractor protection valve is a crucial component that helps with releasing air to the trailer brake lines in case of an emergency. Maintaining the valve's proper functionality is vital for trailer safety checks to ensure that the brake system is functioning correctly. By checking the tractor protection valve, you can ensure that the valve is working efficiently by following the T-check procedures. This simple procedure can prevent brake system failure and save lives.