If you have a stove or lantern that has been heavily used, you will eventually need to refurbish or replace the generator and pump assembly.
The pump assembly contains a plunger made of rubber or leather.
Over time, especially if the plunger assembly has not been lubricated, the plunger will become dry and rigid to the point it will no longer form a seal inside the plunger tube. This prevents pressurizing the reservoir.
With needle-nose pliers, remove the C-clip from the plunger assembly cap and remove the pump assembly. The leather skirt will often be upturned. Immerse the skirt for about an hour in fresh motor oil until it regains suppleness. Stretch and fold the skirt down toward the terminal end of the plunger to form an umbrella and reinstall. Replace the C-clip, and it should form a seal.
Use pliers to unscrew the generator tube from the body, but be careful not to pinch and deform the tube. When the thread bond breaks, unscrew the tube and remove it from the body.
With an appropriate size wrench, loosen the generator fitting at the valve. Turn the valve wheel counter-clockwise until it is open and pull the assembly from the valve housing.
Grip the valve stem firmly with pliers and turn the valve wheel counter-clockwise to remove the valve stem from the generator stem. That should leave you with the generator tube, generator stem, spring, valve and valve wheel separately.
To remove the valve body from the tank, place the valve in a vise, twist the tank counter-clockwise and remove the valve.
Clean the brass fittings with solvent such as gun cleaner, carburetor cleaner, gasoline or a vinegar/soda solution.
Shoot carburetor cleaner through the generator tube to remove carbon deposits.
Then, with the valve assembly in hand, slide the cleaner rod into the bottom of the tube to plunge out the small bottom hole in the tube.
Remove and wipe the cleaner rod, and lightly scrub it with fine steel wool to…