Using a flat tip 5/16 inch screwdriver, rotate adjusting screw (fig. 4-1) (27) as required for an indication
of 130 5 PSIG on the test pressure gauge. Press the purge button, and repeat until no further adjust-
ment is necessary.
Pour new silicone fluid (item 10, App. F) into spring retainer (26) until the fluid level reaches within
1/8 inch below top of spring retainer.
Press the purge button and recheck the pressure test gauge several times to check stability of setting.
If correct pressure holds for one minute, adjustment is complete. Turn off the high pressure air supply
and slowly open the pressure test gauge bleeder screw. Disconnect the first stage regulator from the
high pressure supply and remove the pressure test gauge.
Proceed to the first stage reassembly instructions, (para b (26). above). Care
should be exercised to prevent spillage of the silicone fluid.
4-14 SECOND STAGE REGULATOR (FIG. 4-2).
Second Stage Regulator Disassembly.
With a flat tip 3/16 inch screwdriver, loosen and remove the rim clamp screw (fig. 4-2) (7) and rotate
the rim clamp (6) so a wrench can be placed on the inlet fitting (12).
With a 3/4 inch open end wrench applied to the inlet fitting (12) and a 11/16 inch wrench applied to
the hose connector (27), unscrew and remove hose assembly (26) from the second stage regulator.
With tool 1588-13, remove O-Ring (28) from the hose connector (27).
With a 3/4 inch open end wrench, unscrew and remove the inlet fitting (12).
With tool 1588-13, remove the inlet fitting O-Ring (13).
Remove rim clamp (6), box top (5). and diaphragm (6).
Place the box top (5) on a flat surface with the interior of the box top facing upward. With circlip pliers
remove retainer ring (3). Remove the purge button (2) and button spring (4).
Place the retainer wrench (part 1100-05) on the disc retainer (15). Rotate the retainer wrench until
the four prongs of the wrench enter the four slots on the head of the retainer (15). Using a 1/4 inch
box wrench, hold nut (20) and rotate retainer wrench counterclockwise until the nut is flush with the
end of the disc retainer threaded stem. Grasp the box bottom (ii) firmly and apply forward pressure
on the retainer wrench. This will permit lever (18) to drop down. Forward pressure can be maintained
by placing the knurled end of the retainer wrench in the palm of the hand, placing the thumb under-
neath the box bottom air intake, and placing the index and middle finger over the box bottom rim. Lift
up and remove lever (18) from the grooved interior sections of the box bottom.
Remove disc (14), disc retainer (15), and disc and retainer spring (16) by rotating the retainer wrench
counterclockwise, while holding nut (20) with a 1/4 inch box wrench.
(10) Remove nut (20), spacer (19) and washer (17).
(11) With tool 1588-13, press the inner edge of the head of the disc retainer (15) and remove the disc (14).
(12) Using a diagonal cutter, cut mouthpiece clamp (22). Remove the mouthpiece clamp (22), and the
(13) Apply hot water (approximately 110 F) to the connecting area of the exhaust tube (9) for approxi-
mately five minutes, then pull outward on one end of the tube until it separates from the box bottom
(14) Pull the exhaust valve (10) out of the box bottom (11).
(15) Proceed to Section III. paragraphs 4-7 and 4-8 for cleaning, inspection, and lubrication of parts.