Air bleed-off on Benjamin Marauder ...

My Marauder suddenly began leaking air from the fill port during some recreational shooting today. The pressure charge had been holding steady around 1500 psi and after charging it to 2750 psi, I shot about ten pellets and suddenly heard a hissing noise coming from the cap area. I waited until the pressure bled down and removed the cap; when pressure was almost at zero, I removed the fill port itself. On the inside, there's a slotted valve and it is able to rotate using a flat-blade screwdriver (this might be the pressure valve but could find no schematic for the port itself). Using air from the compressor, I was able to remove this valve and under close inspection found the o-ring eroded with pieces left inside the fill port bore. The area was cleaned and the bad o-ring removed; it was replaced with an o-ring from a kit, AS568 with I/D of 1/8" to O/D of 1/4". After installing this new o-ring and reinserting the valve back into the bore, then adding teflon tape to the fill port threads, I threaded the port back into the rifle and repressurized the system. No leaks and all good. And such an easy fix.