(d) Run the compressor until it turns itself off at 80 psi. The unloader
valve should not discharge air.
(e) Turn the adjusting screw clockwise (use light pressure on the screw
driver) until air just begins escaping through the unloader valve.
Turn the adjusting screw clockwise one and on-half more turns.
(g) Tighten the lock nut. Be sure the adjusting screw does not move
when tightening the lock nut.
(h) Replace the pressure switch cover. Test the unloader valve by
performing an operational checkout. Refer to Lesson 2, paragraph 2-2.
(i) If air is discharging from the unloader valve, remove the unloader
valve, inspect, and clean or replace the valve seat pin assembly.
c. Disassemble and Repair the Dryness Indicator. If the dryness indicator is
not blue, regenerate the drying chamber using the following procedures.
(1) If the dryness indicator is pink, run the compressor for approximately
three hours without drawing any air from the storage tank.
(a) If the dryness indicator does not start to turn blue, follow the
procedures in paragraph 4-3c(2) below.
(b) If the dryness indicator starts to turn blue, continue to run the
compressor until it is blue.
(2) If the dryness indicator is white or does not start to turn blue, drain the
storage tank and allow the compressor to run for five to seven nights.
(3) If the dryness indicator still does not turn blue, replace the dryness
If the disk does not remain blue, replace the drying chamber.
d. Disassemble and Repair the Motor and Compressor Assembly. To repair
or replace any damaged or worn parts, you must disassemble the compressor
assembly. Before disassembly, verify any suspected damage to the reed valves. Refer
to figure 4-6.