Uplinker,
You raise an interesting point, It looks as if the self-styled "greasemonkey" is now away fixing planes, so, FWIW, here's my take on it.
As you well know, an accumulator precharge pressure can only be checked when its system is depressurised.
AFAIK, there is no ECAM warning for low air pressure in an accumulator. (We used to have LAF accumulators in the flight-control system, and they did have an ECAM warning of low precharge pressure, which frequently used to appear on shutdown after a long flight [cold soak], until the ambient air warmed them up.)
For beginners, a system accumulator stores fluid to helps cater for sudden changes in demand. To reduce surges in system pressure, a cushion of "air" is provided. This is separated from the fluid by a diaphragm or piston. The accumulator itself can be likened to the cylinder of a car engine. (In practice, it looks like an oxygen bottle, with a pressure gauge at the end where the "air" (nitrogen) is.) The fluid pressure forces the diaphragm to squash the air until the air pressure balances the fluid pressure. When the system itself is depressurised, the pressure of the air forces the diaphragm to the end of the accumulator, forcing fluid back towards the hydraulic reservoir. The air precharge falls to its nominal pressure, which can now be checked and adjusted by your "greasemonkey". Typically, it may be between 1000psi and 2000psi, but I forget the figure for the A320. (Remember, system pressure is 3000psi.)
What happens if the precharge is lost completely, due to a faulty accumulator? Next time the system is pressurised, the diaphragm will shunt rapidly the full length of the accumulator, hitting the end-stop. Thereafter, the pressure in the system will be less stable than usual.
This is, I think, what
Uplinker has in mind. Could this rapidly-fluctuating pressure lead the PTU to "bark" intermittently, perhaps without triggering either a "SYS LO PRESS" warning, or even the PTU message on the ECAM Memo?
By the way, a quick look on the 'net shows there may have been a batch of
faulty accumulators in circulation a year or two ago.
IIRC, one or both of the Green and Yellow system accumulators, like the Green reservoir, may be up on the keel beam, and therefore only accessible by dropping one or both main L/G doors. (That's easily done, but standing on the main wheels is not high enough unless you are very tall, so you need steps. Perhaps it is a job for
IFixPlanes, after all.
)