How many pounds of leakage is acceptable when using the Brake Pipe Leakage Method or the Automated Brake Pipe Leakage function?

• A. No more than 2 psi in one minute
• B. No more than 5-psi in one minute
• C. No more than 8 psi in one minute
• D. No limit as long as the train stops

Answer: (B)

The test measures how quickly brake pipe pressure leaks away during a leakage check. In both the Brake Pipe Leakage Method and the Automated Brake Pipe Leakage function, you isolate the brake pipe and watch the pressure fall over one minute. The acceptable rate is a drop of no more than 5 psi in one minute. This limit ensures there’s only minimal leakage so braking performance remains reliable between inspections. If the pressure falls faster than 5 psi per minute, the test fails and maintenance is needed. A drop of 2 psi is within the limit, while an 8 psi drop exceeds it. No limit isn’t correct because there must be a safety threshold for leakage.