Hitachi NR90GC - 3-1/2" Gas Powered Clipped Head Framing Nailer Technical Data And Service Manual page 52

Fig. 43
Cylinder Ass'y [42]
Chamber [24]
Pushing Lever Arm (A) [60] or (B) [62]
Split of the Roll Pin D3 x 32 [25]
Pushing Lever Arm (A)
[60] or (B) [62]
--- 49 ---
Roll Pin D3 x 32 [25]
Support the Chamber
[24] with a pedestal.
Fig. 44
Chamber [24]