Hello, has anyone made a complete Benjamin hand pump o-ring kit from either a Metric or SAE Harbor Freight o-ring assortment?
Benjamin pump rebuild o-rings
- Thread starter Cbourbeau32
- Start date
Here’s a diagram with the sizes:
v
The -007 final stage O-ring absolutely, positively must be a 90 durometer. Anything softer will meet an early demise. Preferably a Disogrin cast polyurethane, not standard polyurethane. Theoringstore has them last I checked. Otherwise go with a Buna-N in 90 durometer…you can find those at a broader selection of suppliers.
Everywhere else in the pump, 70 durometer Buna-N works nicely. Even those from a Harbor Freight assortment will likely outlast even the preferred cast urethane O-ring on the inner rod.
vThe -007 final stage O-ring absolutely, positively must be a 90 durometer. Anything softer will meet an early demise. Preferably a Disogrin cast polyurethane, not standard polyurethane. Theoringstore has them last I checked. Otherwise go with a Buna-N in 90 durometer…you can find those at a broader selection of suppliers.
Everywhere else in the pump, 70 durometer Buna-N works nicely. Even those from a Harbor Freight assortment will likely outlast even the preferred cast urethane O-ring on the inner rod.
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