Removed the Pressure Sensor. 2 O-rings in brass supports rings on sensor threads. Would have expected only 1. However 1 O-ring is damaged.
However, as per post #18 I now know why you need the "long tool" to replace the sensor. The part into which the sensor screws is free to "wander up & down inside the air cylinder".
A little knowledge springs to mind.

So assuming sensor is okay it needs a new O-ring. Guess it's bite the bullet and off to Pickering Guns to pay whatever the bill.


Al