Crosman Mark I and II reseal: Part 2

by Tom Gaylord
Writing as B.B. Pelletier


Crosmnan Mark schematic

Today’s report is another guest blog from reader Ian McKee who writes as 45 Bravo. He’s going to finish the report on resealing the Crosman Marks I and II CO2 pistols.

If you’d like to write a guest post for this blog, please email me.

History of airguns

Part 1 — resealing the end cap

Over to you, Ian.

Crosman Mark I and II reseal

Ian McKee 
Writing as 45 Bravo

This report covers:

  • Disassembly
  • Bolt removal
  • Hammer spring
  • Remove trigger guard
  • Remove the valve
  • Prep and assembly
  • The 4 o-rings in the pistol
  • Piercing cap o-rings
  • Assemble the pistol in the reverse order
  • Test the function

So, your Crosman MK1 is still leaking, even after you replaced the seal in the piercing cap as we covered in an earlier blog. 

There are only 4 o-rings in this pistol, only 3 have constant gas pressure on them when the gun is charged, and 2 of those are in or on the piercing cap assembly, and those we already covered.  read more