how to check tractor protection valve

Tractor protection valve is a safety feature attached to tractor trailer air brake systems. It ensures that in case of a break or detachment of the connecting hoses between the tractor and the trailer, the emergency brake is automatically applied to the trailer. This valve also ensures the tractor can charge the trailer air brake system. This component provides a crucial safety factor and is required to be inspected periodically to ensure its proper functioning. This article will provide steps for checking the tractor protection valve to ascertain its functionality.

Step 1: Pre-Inspection Checks

Before commencing with the inspection of the tractor protection valve, inspect the air brake system of the trailer for any leaks or damage. Ensure that the air pressure is above the critical cutoff pressure of the valve, which is generally set to 60 psi. Inspect the connecting hoses for any visible damage and check for any air leaks between the tractor and the trailer.

Step 2: Locate the Tractor Protection Valve

The location of the protection valve on the tractor brake system varies with different manufacturers and models. Refer to the tractor's user manual for the specific location of the valve. However, the valve is generally located near the firewall of the engine compartment. Identify the valve and mark its location for ease of access.

Step 3: Inspect the Valve

Check the valve for any visible signs of damage or malfunction, such as leaks, cracks, or worn-out parts. The valve should be clean of dirt and grime. Clean the valve if necessary. Check the connection between the valve and the brake system for a secure fit.

Step 4: Test the Valve

Start the tractor and allow the air pressure to build up. Then, apply the tractor's brakes, and the protection valve should operate as the pressure in the trailer's air tank drops. Check the valve function by releasing the trailer emergency brakes while parked. If the valve is functioning correctly, the trailer brakes should be applied as the air pressure from the tractor's brake system is released.

Step 5: Further Checks

If the inspection and testing indicate a malfunctioning valve, it is recommended to replace the valve with a new one. It is also essential to inspect other related components of the tractor and trailer brake systems, such as the air dryer, air compressor, air tanks, and associated electrical connections.

Conclusion

Checking the tractor protection valve is an essential safety practice that requires a little bit of knowledge and guidance. Regular inspection of this component should be performed to ensure the proper functioning of the trailer's emergency brakes. Follow the steps outlined above to ensure the tractor protection valve is working correctly, and if needed, replace it as soon as possible to avoid potential accidents on the road.