(2) Using wrench, unscrew the flared tube nuts and other fittings.
(3) Lift out the pressure regulator.
c. Installation of pressure regulator. Line up pressure regulator, regulator tube, diffusion-pipe assembly, and fittings carefully so they will not be damaged when threads are tightened. Start threads with the hands. Apply only moderate wrench pressure to complete tightening. Replace carrier or carrier pack if either has been removed.
d. Adjustment of pressure regulator. The pressure regulator ordinarily requires no attention other than checking and tightening connections with the regulator tube and the diffusion-pipe assembly. If a defect in the regulator is indicated by falling off of the range of the weapon or by frequent breakage of the safety-head diaphragm ([Par 56 b]), the following procedure should be carried out. (When using wrenches, do not apply excessive force.)
(1) Remove the filling plug ([Par 69 b]) and ignition cylinder. ([Par 30 a])
(2) Fill the fuel tanks with 4 gallons of water (or fuel).
(3) Connect the 0-to 500-pound fuel-tank testing gage, found in the service kit, to the filling-plug hole. Tighten plug of gage with wrench.
(4) Charge the pressure tank to a pressure of 1,800 pounds per square inch. (Pars [32] and [33])
(5) Open the pressure-tank valve.
(6) Read the pressure on the gage. If 350 to 390 pounds is indicated, omit steps (7) through (10).