The Shackleton's breaking system operates of pneumatic pressure provided by engine driven pumps. This is the stored in tanks until needed. Prior to moving the aircraft or start up, this pressure is built up with the assistance of the ground crew and the Nitrogen Bottle Trolley. Sadly over time it has bee noticed that the system is not holding its pressure like it used to, so some investigation was required.
The pneumatic crate was semi removed for leak detection on all the fixtures, fitting and pipework. This work carried on further back throughout the entire system until the source of the issue was found.
The offending article, an AHO5712 pressure reducing valve was found to be faulty and leaking pressure. This was removed and a new serviceable item fitted in its place. This valve was then successfully pressure tested to 500 psi.
The pressure held until our next visit a couple of weeks later.