Coleman pump disassembly:
* Withdraw Piston Assembly
* Unscrew and withdraw 1/8" Sq. brass Needle valve
* Make tool with 1/8"x1/8"x1/2" lug on one end,
  at least 5" long with wrench fitting on other.
* Insert lug into slot in check-valve/needle-valve-seat
  in bottom of pump cylinder and robustly unscrew
  R.H thread.