Never replaced the seals in a SN-325? video below explains the break down and reassembly.

Senco LB3499 + BC0178 + SN325 O-ring Kit
Senco LB3499 + BC0178 + SN325 O-ring Kit
Senco Seal LB3499 + BC0178 + O-ring kit For Nailer SN-325 Ships Free US
Senco LB3499 seal + BC0178 top bumper
Senco LB3499 seal + BC0178 top bumper
For the Senco SN325 nailer
1 LB3499 washer firing valve seal
1 BC0178 top piston bumper
 Price includes shipping in the US
Available Qty: 22
Aftermarket SN325 Lower Bumper BB0151
Aftermarket SN325 Lower Bumper BB0151
1 Aftermarket Bumper for the SN325
Part # BB0151
Price includes Shipping in the US
Senco SN325 Feeder Spring
Senco SN325 Feeder Spring
Senco SN325 Feeder Spring
Includes
Spring KB5061
Pin GB0216
Instructions
Available Qty: 1


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