Low Suction
Had a navigation flight planned today but discontinued the flight due to a very low suction reading. The needle had not moved since the start up and there was a hissing sound. Obviously perhaps a small leak but just wanted to see if others would have done the same? It was a CAVOK day, no IFR, just a VFR nav.
The suction is a particular problem with this a/c and have been told since that it usually comes up during run up/ during flight.
Safe call or Over cautious? I will let the jury decide?
RNAV