What is the maximum allowable leakage at the exhaust port of the relay valve?

The maximum allowable leakage at the exhaust port of the relay valve is specified as one inch soap bubble every three seconds. This standard exists to ensure the proper functioning of the relay valve within a vehicle's braking system. If leakage exceeds this threshold, it may indicate a malfunctioning valve or an issue within the brake system that could lead to reduced braking efficiency and overall safety concerns.

One inch every three seconds allows for a minimal yet acceptable level of leakage under controlled conditions, ensuring that the braking system remains effective while still allowing some minor permeability for operational purposes. A higher leakage rate, as suggested by some of the other options, would compromise the valve’s performance. Additionally, having zero leakage, while ideal, is often not a practical expectation due to the nature of wear and tear in mechanical systems. Regular maintenance and inspections are necessary to adhere to this standard and to ensure that the braking system remains reliable and safe for operation.