A comprehensive strip-down and replacement of critical rubber components and valves, usually every 4.5 to 6 years.
The DV is the "brain" of the braking system. G73 specifies how to clean, overhaul, and test the sensitivity of the valve to ensure it responds correctly to pressure drops in the brake pipe. 2. Brake Cylinder rdso technical pamphlet g73
Ensuring pressure drop is within permissible limits. rdso technical pamphlet g73
Daily checks for air leaks and manual brake testing before a train departs from a siding. Testing Procedures rdso technical pamphlet g73