Troubleshooting Guide - Aqua Lung Micra ADJ Service & Repair Manual

Micra ADJ Second Stage Service & Repair Manual
SYMPTOM
Leakage or freeflow from
second stage
NOTE: Test with second stage
adjustment knob turned in
clockwise between 2 & w turn.
Low purge or excessive work
of breathing (full cylinder)
External air leakage
Water entering second-stage
CAUTION: Recommended treatments which require disassembly of the regulator
must be performed during a complete overhaul, according to the prescribed proce-
dures for scheduled, annual service. Do not attempt to perform partial service.
Table 1

Troubleshooting Guide

Micra ADJ Second-Stage
POSSIBLE CAUSE
1. High first-stage intermediate pressure.
(should be 140 ±5 psi)
2. LP seat(15) damaged or worn.
3. Crown(12) incorrectly adjusted,
lever(5) set too high.
4. Crown(12) sealing surface damaged.
5. Poppet spring(25) damaged.
1. Low intermediate pressure.
(should be 140 ±5 psi)
2. Lever(5) not properly engaged with
retaining sleeve(27).
3. Crown(12) incorrectly adjusted,
lever(5) set too low.
4. Intermediate pressure hose(8)
clogged or obstructed.
1. Intermediate pressure hose loose.
(Immersion Test)
2. Crown O-ring(11) damaged.
3. Box bottom(14) damaged.
1. Hole in mouthpiece(17).
2. Demand diaphragm(4) damaged.
3. Exhaust diaphragm(6) damaged.
4. Adjustment vane switch O-ring(15)
dirty, damaged, or worn.
5. Diaphragm improperly seated
between box bottom(14) and
purge cover(3).
6. Box bottom damaged.
(Check exhaust valve sealing surface.)
7. Valve body O-ring(20) damaged.
8. Cap nut(31) loose.
9. Cap nut O-ring(30) damaged.
TREATMENT
1. Refer to first-stage Troubleshoot-
ing Guide.
2. Replace LP seat.
3. Reset crown and perform Final
Tuning & Testing procedures.
4. Replace crown.
5. Replace poppet spring.
1. Refer to first-stage Troubleshoot-
ing Guide.
2. Disassemble and inspect condi
tion of retaining sleeve.
3. Reset crown and perform Final
Tuning & Testing procedures.
4. Clean or replace hose.
1. Tighten to 40 inch-lbs at female
second-stage fitting.
2. Disassemble and replace O-ring.
3. Disassemble and replace box
bottom.
1. Replace mouthpiece.
2. Replace demand diaphragm.
3. Replace exhaust diaphragm(s).
4. Disassemble and replace O-ring.
5. Disassemble and properly re-
assemble. (Check for distortion.)
6. Disassemble and replace box
bottom.
7. Disassemble and replace O-ring.
8. Snug cap nut.
9. Disassemble and replace O-ring.
© 1997 U.S. Divers Co., Inc.
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