Table 1 - Troubleshooting Guide - U.S. Divers Impulse Service & Repair Manual

14
SYMPTOM
Leakage or freeflow from
second stage
NOTE: Test with second stage
adjustment knob turned in
clockwise between 1/2 - 3/4 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.
© 1997 U.S. Divers Co., Inc.
Table 1
Troubleshooting Guide
Impulse Second-Stage
POSSIBLE CAUSE
1. High first-stage intermediate pressure.
(should be 140 ±5 psi)
2. LP seat(27) damaged or worn.
3. Crown(21) incorrectly adjusted,
lever(26) set too high.
4. Crown(21) sealing surface damaged.
5. Poppet spring(28) damaged.
1. Low intermediate pressure.
(should be 140 ±5 psi)
2. Lever(26) not properly engaged with
Poppet/ LP Seat Assy(27).
3. Crown(21) incorrectly adjusted,
lever(26) set too low.
4. Intermediate pressure hose(8)
clogged or obstructed.
5. Deflector clip(25) installed incorrectly.
1. Intermediate pressure hose loose.
(Immersion Test)
2. Crown O-ring(20) damaged.
3. Box bottom(6) damaged.
1. Hole in mouthpiece(16).
2. Demand diaphragm(5) damaged.
3. Exhaust diaphragm(19) damaged.
4. Vane Adjustment Switch O-ring(13)
dirty, damaged, or worn.
5. Diaphragm improperly seated
between box bottom(6) and
purge cover(2).
6. Box bottom(6) damaged.
(Check exhaust valve sealing surface.)
7. Valve body O-ring(22) damaged.
8. Spacer bushing(12) worn or damaged.
Impulse Second Stage Service & Repair Manual
TREATMENT
1. Refer to first-stage Troubleshoot-
ing Guide.
2. Replace Poppet/ LP seat Assy.
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 Poppet/ LP Seat Assy.
3. Reset crown and perform Final
Tuning & Testing procedures.
4. Clean or replace hose.
5. Remove clip and reinstall.
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. Disassemble and replace spacer
bushing.